Unit 11 The Simple Past
GRAMMAR FOR WRITING
Activity 1, page 162
1. wanted 2. asked 3. started 4. seemed 5. used
6. played 7. looked 8. appeared 9. helped 10. moved
11. showed 12. reported 13. turned 14. died 15. worked
16. included 17. received 18. decided 19. tried 20. called
21. happened 22. added 23. learned 24. continued 25. opened
26. lived 27. created 28. believed 29. suggested 30. liked
Activity 2, page 164
Answers will vary.
Activity 3, page 164
Answers will vary.
Activity 4, page 165
1. was; were 2. had 3. did 4. said 5. came
6. got 7. went 8. made 9. took 10. thought
11. knew 12. told 13. saw n14. found 15. began
16. felt 17. became 18. gave 19. left 20. wrote
21. heard 22. sat 23. stood 24. put 25. ran
26. kept 27. held 28. brought 29. lost
Activity 5, page 166
Answers will vary.
Activity 6, pages 166–167
1. I got a cold two or three days ago.
2. Last night, I felt a little sick.
3. I took aspirin, and then I went to bed.
4. I usually get up at 8 a.m., but I got up at 6:30 a.m. today.
5. I was very sick, so I went to see my doctor.
6. He said I had a very high fever.
7. He told me to go home and rest.
8. On the way home, I saw a drugstore.
9. I found some strong medicine there.
10. At home, I took the medicine, and I feel better now.
Activity 7, page 168
1. My vacation to Florida was not fun.
2. My flight did not leave on time.
3. I did not catch my connecting flight.
4. My suitcase did not arrive in Florida.
5. The hotel did not have my reservation. / My hotel did not
have the reservation.
6. I did not like the room they gave me.
7. The weather was not good.
8. I did not have fun.
BUILDING BETTER VOCABULARY AND SPELLING
Activity 8, page 169
Answers will vary.
Activity 9, page 170
1. sauce 2. automobile 3. laundry 4. wall 5. cough 6. salt
Activity 10, page 170
1. Au; August 2. a; tall 3. aw; raw 4. au; sauce 5. o; wrong
6. aw; awful 7. au; daughter 8. a; always 9. ou; thought
10. aw; drawer
Activity 11, page 171
1. autumn 2. also 3. sauce 4. almost 5. law 6. draw
7. ball 8. long 9. fall 10. taught 11. author 12. call
Activity 12, page 171
1. call 2. walk 3. tall 4. raw 5. fall 6. talk
7. almost 8. law 9. always 10. sauce 11. cough
12. thought
Activity 13, page 171
1. B. bought 2. A. fall 3. A. small 4. A. all 5. B. also
6. B. wrong 7. A. sauce 8. B. cause 9. B. raw 10. A. caught
11. B. author 12. A. almost 13. A. straw 14. B. salt 15. A. daughter
16. B. strong 17. A. draw 18. B. cough 19. B. tall 20. B. walk
Activity 14, page 172
1. B. caught 2. D. almost 3. C. practice 4. D. daughter 5. B. school
6. D. sometimes 7. B. important 8. C. laundry 9. A. study
10. A. future 11. C. continue 12. A. smoke 13. D. juice
14. B. cousin 15. C. amazing 16. B. pick 17. C. after
18. A. problem 19. C. trouble 20. A. little 21. D. reason
22. B. Wednesday 23. A. famous 24. D. usually 25. B. Chinese
BUILDING BETTER SENTENCES WITH
VOCABULARY
Activity 15, page 173
1. Omar studies English at the community college.
2. The final test for his class was yesterday. / Yesterday was
the final test for his class.
3. The test was very difficult.
4. The exam was long, and it took Omar two hours.
5. The test did not have any short questions.
6. Omar did not know the answers to three questions.
7. He just learned his score.
8. He got a score of 81.
Activity 16, page 174
Activity 17, page 175
1. sauce; Maria ate her pasta with tomato sauce.
2. wrong; Ling had only one wrong answer on the test, so her
score was 95.
3. tall; My brother is very tall, but my sister and I are short.
4. thought; My sister thought about the problem for a long time.
5. always; We really like tennis, so we always play tennis on
Mondays and Thursdays.
6. August; The month before September is August.
7. awful; The food is awful, and I cannot finish it.
8. daughter; My wife and I have three sons and one daughter.
9. draw; It is very difficult to draw people.
10. raw; Sushi uses raw fish.
WRITING
Activity 18, page 176
A Special Event
Last year, my birthday was very special. My friend Nadia
came to visit. She cooked a delicious birthday dinner for me.
She knows how to cook well. A meal by Nadia is always a special
event. This meal was extra special. Nadia surprised me. We went
to school together and have the same friends. She invited these
friends to celebrate, too. It was the best birthday ever.
Activity 19, pages 176–177
A Special Event
Last year, my graduation was very special. My Aunt Nadia
came to visit. She cooked a delicious graduation dinner for me
and my family. She knows how to cook well. A meal by Aunt
Nadia is always a special event, but this meal was extra special.
Aunt Nadia surprised us. She baked a huge cake. She invited
all my friends to come over for cake, too. It was the best
graduation celebration ever.
Activity 20, page 177
Answers will vary.
Unit 12 Complex Sentences
GRAMMAR FOR WRITING
Activity 1, pages 180–181
Activity 2, page 182
1. Because tomorrow is Lim’s birthday, I want to bake a cake for him.
2. Because chocolate is Lim’s favorite kind of cake, I want to make a chocolate cake.
3. Before I can make Lim’s cake, I need to go to the store.
4. If I want to make a very big cake, I have to buy a lot of flour and sugar.
5. After the cake cools down, I can put frosting on it.
6. When Lim sees his birthday cake, he will be so happy.
7. Because Lim will be 26 years old, my brother bought 26 candles for his cake.
8. When the cake is ready, my brother will put the candles on it.
9. Because Lim’s sister has a great voice, she will sing “Happy Birthday.”
10. If Lim is happy, everyone will be happy.
Activity 3, page 182
1. a. No comma necessary
b. Because it is sunny today, you should wear a hat.
2. a. No comma necessary
b. Because my language uses a different alphabet, Chinese is difficult for me.
3. a. No comma necessary
b. Because that book has 300 pages, it took me two
weeks to read it.
4. a. Because Marie is from France, she speaks French.
b. No comma necessary
5. a. Because it was so cold outside, Ryan closed the
window in his bedroom.
b. No comma necessary
6. a. No comma necessary
b. Because we want to learn Japanese, we plan to live in
Japan for one month.
7. a. No comma necessary
b. Because some people cannot have any milk products,
they cannot eat cheese.
8. a. No comma necessary
b. Because giraffes are very interesting, they are my
favorite animal.
Activity 4, page 183
1. My sister will study tonight because she has a test tomorrow.
Because my sister has a test tomorrow, she will study tonight.
2. You need an umbrella because it is raining now.
Because it is raining now, you need an umbrella.
3. The class understood the professor easily because she
spoke clearly.
Because the professor spoke clearly, the class understood
her easily.
4. I am going to take my car to the repair shop because it is
making a noise.
Because my car is making a noise, I am going to take it to
the repair shop.
5. Many Irish families moved to America in the 1800s because
life in Ireland was difficult.
Because life in Ireland was difficult, many Irish families
moved to America in the 1800s.
6. The word get is difficult to use correctly because it has
many different meanings.
Because the word get has many different meanings, it is
difficult to use correctly.
Activity 5, page 184
1. a. No comma necessary
b. Before most children go to school, they learn the
names of the colors.
2. a. No comma necessary
b. After Jason finished his breakfast, he went to work.
3. a. When my father drives to work, he listens to news on the radio.
b. No comma necessary
4. a. No comma necessary
b. After I added one cup of flour, I added two cups of sugar.
5. a. When Jeff turned on the computer, nothing happened.
b. No comma necessary
6. a. No comma necessary
b. When I could not start my car, my friends pushed it.
7. a. No comma necessary
b. Before I left the office, I wrote ten emails.
8. a. When we flew to Alaska, the airline gave us lunch and a snack.
b. No comma necessary
Activity 6, page 185
1. I was so happy when I heard your good news.
When I heard your good news, I was so happy.
2. You should read the bill carefully before you pay it.
Before you pay the bill, you should read it carefully.
3. We watched that long movie before we went to bed.
Before we went to bed, we watched that long movie.
4. I washed my dish and put it in the cabinet after I ate lunch.
After I ate lunch, I washed my dish and put it in the cabinet.
5. Natalia did not speak any English before she went to England.
Before Natalia went to England, she did not speak any English.
6. My sister decided to buy those shoes when she saw the low price.
When my sister saw the low price, she decided to buy those shoes.
Activity 7, page 186
1. a. If you eat more vegetables and less red meat, you may
be healthier.
b. No comma necessary
2. a. No comma necessary
b. If you multiply the two numbers, the answer is 116.
3. a. If a hurricane comes near our area, you should leave.
b. No comma necessary
4. a. No comma necessary
b. If there is meat in this soup, Linda cannot eat it.
5. a. If you have any problems, you should call me immediately.
b. No comma necessary
6. a. If the weather is cold tomorrow, everyone will need a
heavy sweater.
b. No comma necessary
5. a. If you have any problems, you should call me immediately.
b. No comma necessary
6. a. If the weather is cold tomorrow, everyone will need a
heavy sweater.
b. No comma necessary
Activity 8, pages 186–187
1. My sister studies with her friends if she has an important test.
If my sister has an important test, she studies with her friends.
2. You will laugh a lot if you read this book.
If you read this book, you will laugh a lot.
3. The lake will freeze tonight if the weather is really cold.
If the weather is really cold, the lake will freeze tonight.
4. You need to buy a new computer if your computer is broken.
If your computer is broken, you need to buy a new computer.
5. The ticket will be expensive if Sarah travels to China in November.
If Sarah travels to China in November, the ticket will be expensive.
6. I look up the meaning of a word in a dictionary if I do not know it.
If I do not know the meaning of a word, I look it up in a dictionary.
Activity 9, page 187
Possible Answers:
1. Because I need to learn English to get a better job, I
selected this school. / I selected this school because I need
to learn English to get a better job.
2. When my family takes a trip, our dog stays at my friend’s
house. / Our dog stays at my friend’s house when my family
takes a trip.
3. Before everyone entered the office, they took their coats
off. / Everyone took their coats off before they entered the
office.
4. If you work very hard this year, you will learn a lot. / You will
learn a lot if you work very hard this year.
5. After you add the onions and the other vegetables to the
pan, you need to cover it. / You need to cover the pan after
you add the onions and the other vegetables to it.
6. Because we do not have an Internet connection, we cannot
use social media. / We cannot use social media because we
do not have an Internet connection.
7. When the weather in our area is very hot, no one wants
to go outside. / No one wants to go outside when the
weather in our area is very hot.
8. Because my new phone takes beautiful photos, I do not
need my camera anymore. / I do not need my camera
anymore because my new phone takes beautiful photos.
BUILDING BETTER VOCABULARY AND SPELLING
Activity 10, page 188
Answers will vary.
Activity 11, page 189
1. bull 2. cookie 3. woman 4. book 5. sugar 6. push
Activity 12, page 189
1. oo; book 2. u; sugar 3. u; full 4. oo; look 5. oo; wool
6. u; pull 7. oo; understood 8. oo; good 9. oo; foot 10. u; put
Activity 13, page 190
1. cook 2. push 3. should 4. bush 5. cookie 6. stood
7. could 8. wood 9. woman 10. book 11. took 12. would
Activity 14, page 190
1. good 2. book 3. put 4. foot 5. could 6. full
7. push 8. wool 9. bush 10. pull 11. woman 12. should
Activity 15, page 190
1. A. book 2. B. cookie 3. A. bull 4. B. could 5. B. woman
6. B. cook 7. B. put 8. B. took 9. B. pull 10. B. foot
11. A. full 12. A. should 13. A. good 14. A. look 15. B. stood
16. B. wood 17. B. bull 18. B. would 19. B. sugar 20. A. wool
Activity 16, page 191
1. B. box 2. D. language 3. C. many 4. D. said 5. A. funny
6. C. lemon 7. C. stop 8. D. awful 9. D. please 10. B. sugar
11. A. everything 12. D. women 13. A. never 14. A. happen
15. A. could 16. D. famous 17. C. practice 18. D. student
19. D. because 20. D. took
BUILDING BETTER SENTENCES WITH
VOCABULARY
Activity 17, page 192
1. My favorite food is pizza.
2. I like pizza because it has a lot of cheese.
3. I wanted a pizza yesterday, so I went to a pizza restaurant.
4. The name of the restaurant was Pizza Country. / Pizza
Country was the name of the restaurant.
5. I went to this restaurant because a friend told me about it.
6. When I walked inside, I had a good feeling about the place.
7. The restaurant looked nice, and the pizza menu was long.
8. After I read the menu, I decided to order the chicken pizza.
9. When I tried my pizza, I was happy with my choice.
10. If you want to eat a really delicious pizza, I recommend this
restaurant.
Activity 18, page 193
Activity 19, page 194
1. foot; The plural of foot is feet.
2. put; After you wash the dishes, you need to put them away.
3. sugar; My friend likes a little sugar in her coffee.
4. full; Our new boss is full of new ideas for the company.
5. book; Remember to return the book to the library.
6. pull; You have to pull the door really hard to close it.
7. wool; When the weather is cold, many people wear a heavy
wool sweater.
8. should; You should do the homework for every class.
9. understood; Maria, Thomas, and Amina understood
everything on the test yesterday, so their scores were very high.
10. look; Zebras look like horses with stripes.
WRITING
Activity 20, pages 194–195
My First Job as a Teacher
This story is about my first job as a teacher. In May 2009,
I finished college. I got a degree in education, and I wanted to
become a teacher. I really wanted to teach in another country.
I looked on the Internet for information about a job in Brazil.
When I found a really good job posting, I wrote an email to the
school. Soon I received a job offer from the school. After I got
that letter, I asked my family for advice. My parents liked the
job, so I accepted it. I taught English in Brazil for three years.
I will never forget my teaching experience in Brazil. It was the
beginning of my career as a teacher.
Activity 21, page 195
My First Job as a Chef
This story is about my first job as a chef. In May 2009,
I finished college. I got a degree in culinary arts, and I wanted
to become a chef. I really wanted to cook in another country,
so I looked on the Internet for information about a job in
France. When I found a really good job posting, I wrote an
email to the restaurant. Soon I received a job offer from the
restaurant. After I got that letter, I asked my family for advice.
My parents liked the job, so I accepted it. I cooked in France for
three years. I will never forget my cooking experience in France
because it was the beginning of my career as a chef.
Activity 22, page 195
Answers will vary.
Unit 13 Adverbs
GRAMMAR FOR WRITING
Activity 1, pages 198–199
Activity 2, pages 199–200
1. My brother and sister are in their classrooms at 8 a.m.
At 8 a.m., my brother and sister are in their classrooms.
2. We were in Madrid in 2011.
In 2011, we were in Madrid.
3. Jose Martinez came to the United States five years ago.
Five years ago, Jose Martinez came to the United States.
4. Jonathan bought a new pair of shoes at the mall yesterday.
Yesterday Jonathan bought a new pair of shoes at the mall.
5. Lucas and I are going to eat lunch at a steak restaurant tomorrow.
Tomorrow Lucas and I are going to eat lunch at a steak restaurant.
6. I play tennis with Maria at the park on Saturday mornings.
On Saturday mornings, I play tennis with Maria at the park.
Activity 3, page 201
1. quick; quickly 2. slow; slowly 3. good; well
4. easy; easily 5. carefully; careful
Activity 4, page 202
Answers will vary.
Activity 5, page 202
Answers will vary.
Activity 6, page 203
1. I like bananas. They are very healthy.
2. I like this chocolate cake a lot. It is so good.
3. The math test was very difficult. Matt did not pass it.
4. Jenna wants to play tennis today, but it is too hot. Maybe
she will play tomorrow.
5. The problems with our car are very serious. We need to buy a new one.
6. Everyone should exercise. It is an extremely important thing to do.
BUILDING BETTER VOCABULARY AND SPELLING
Activity 7, page 204
Answers will vary.
Activity 8, page 205
1. cow 2. crowded 3. bow 4. mouse 5. cloud 6. mountain
Activity 9, page 205
1. ow; town 2. ou; around 3. ow; now 4. ou; round 5. ow; allow
6. ou; south 7. ou; about 8. ou; loud 9. ou; out 10. ow; cow
Activity 10, page 206
1. sour 2. house 3. flower 4. sound 5. pound 6. down
7. loud 8. flour 9. mouse 10. towel 11. now 12. ground
Activity 11, page 206
1. out 2. how 3. about 4. house 5. sound 6. mouse
7. count 8. down 9. allow 10. towel 11. ground 12. crowded
Activity 12, page 206
1. A. house 2. A. pound 3. A. our 4. B. down 5. A. mouth
6. A. mouse 7. B. cow 8. A. about 9. B. shower 10. A. hour
11. A. sour 12. B. allow 13. A. found 14. A. south 15. B. power
16. B. towel 17. B. how 18. A. shout 19. B. crowded 20. A. cloud
Activity 13, page 207
1. D. flower 2. C. famous 3. C. kitchen 4. C. possible 5. C. contain
6. B. should 7. D. family 8. B. pepper 9. B. minutes 10. C. student
11. A. money 12. C. house 13. D. towel 14. D. because
15. A. clothes 16. B. finally 17. C. sauce 18. A. reason
19. D. around 20. D. everybody
BUILDING BETTER SENTENCES WITH
VOCABULARY
Activity 14, page 208
1. Hokkaido is a large island in northern Japan.
2. Sapporo is the capital of Hokkaido. / The capital of
Hokkaido is Sapporo.
3. People visit Hokkaido in the winter because they want to
see the snow and ice. / People visit Hokkaido because they
want to see the snow and ice in the winter.
4. Because Hokkaido is so far north, it has very long winters. /
Because it is so far north, Hokkaido has very long winters.
5. In January, the temperature is around –8 degrees Celsius.
6. There is a snow festival every February.
7. People build huge sculptures with the snow and ice.
8. The Sapporo Snow Festival is very popular.
Activity 15, page 209
Activity 16, page 210
1. south; Mexico is located south of the United States.
2. sound; When my car makes a strange sound, I take it to a mechanic.
3. hour; There are 60 minutes in an hour.
4. about; That movie is about two people from Korea.
5. town; I live in New York City, but I was born in a small town.
6. around; My little brother loves to run around the tree in our backyard.
7. allow; When I was younger, my parents did not allow me to
watch scary movies.
8. loud; Susan does not like that music because it is so loud.
9. out; The opposite of in is out.
10. round; Oranges, balls, and coins are examples of round things.
WRITING
Activity 17, pages 210–211
My Neighbor
I have an elderly neighbor. His name is Mr. Taylor. He is 80
years old, but he drives his car every day. He drives to the coffee
shop every morning. He always goes there. He usually drives to
the supermarket twice a week. He also drives to the post office
twice a week. He is old, so he drives very slowly. Because he is
a slow driver, he has a line of cars behind him. I do not like to
drive on the road with Mr. Taylor because he drives too slowly.
Activity 18, page 211
My Neighbor
I have a teenage neighbor. His name is Tom. He is 18 years
old, and he drives his car every day. He drives to the coffee shop
every morning. He always goes there. He usually drives to the
gym and the mall twice a week. He is young, so he drives very
fast. Because he is a fast driver, he passes many cars. I do not
like to drive on the road with Tom because he drives too fast.
Activity 19, page 211
Answers will vary.
UNIT 14 The Present Progressive
GRAMMAR FOR WRITING
Activity 1, page 215
Jacob is a passenger on Flight 873. He is flying to California.
He is going there because his company is doing business there.
Right now, Jacob is not talking to anyone. He is not eating
anything. He is not drinking anything. Jacob is looking at his
phone. He is listening to his favorite music. He is a very happy
passenger right now.
SUBJECT FORM OF BE (NOT) VERB + ING
1. He is flying
2. He is going
3. His company is doing
4. Jacob is not talking
5. He is not eating
6. He is not drinking
7. Jacob is looking
8. He is listening
Activity 2, pages 216–217
1. going 2. trying 3. looking 4. making 5. getting
6. using 7. saying 8. coming 9. working 10. talking
11. taking 12. running 13. playing 14. watching 15. giving
16. sitting 17. waiting 18. living 19. seeing 20. leaving
21. standing 22. holding 23. telling 24. asking 25. thinking
26. moving 27. deciding 28. trying 29. putting 30. following
Activity 3, page 218
Possible answers:
1. She is living in Canada now.
2. I am trying to find a new job right now.
3. They are sitting on a bench at this moment.
4. She is trying to find a new job.
5. They are living in Canada right now.
Activity 4, page 218
Answers may vary.
Activity 5 page 218
1. The Johnson family is taking a trip today.
2. They are going to California.
3. Mr. Johnson is driving.
4. The children are listening to the radio.
5. They are enjoying this trip very much.
BUILDING BETTER VOCABULARY AND SPELLING
Activity 6, page 219
Answers may vary.
Activity 7, page 220
1. toy 2. boil 3. point 4. coin 5. oil 6. noise
Activity 8, page 220
1. oy; enjoy 2. oi; point 3. oy; employer 4. oy; destroy
5. oi; oil 6. oi; choice 7. oi; voice 8. oi; boil
9. oi; coin 10. oy; employee
Activity 9, page 221
1. choice 2. voice 3. joy 4. oil 5. employee 6. noise
7. boil 8. join 9. destroy 10. enjoy 11. poison 12. point
Activity 10, page 221
1. boy 2. boil 3. coin 4. enjoy 5. point 6. employee
7. poison 8. toy 9. choice 10. destroy 11. employer 12. voice
Activity 11, page 221
1. B. boil 2. A. boy 3. B. oil 4. A. destroy
5. B. poison 6. B. point 7. A. employee 8. B. join
9. B. choice 10. B. voice 11. A. joy 12. A. enjoy
13. B. coin 14. B. noise 15. A. employer 16. B. toy
Activity 12, page 222
1. B. choice 2. C. next 3. B. goals 4. D. sugar
5. D. because 6. A. reason 7. A. with 8. C. people
9. A. tomorrow 10. D. family 11. D. destroy 12. C. spend
13. B. include 14. D. shower 15. B. doctor 16. C. right
17. C. noise 18. D. always 19. D. daughter 20. A. hungry
BUILDING BETTER SENTENCES WITH
VOCABULARY
Activity 13, pages 222–223
1. Lucas is shopping at the supermarket right now. / Right
now, Lucas is shopping at the supermarket.
2. He is buying many things.
3. Lucas is planning a big dinner for his cousin’s birthday.
4. He is getting some delicious food for tonight’s big dinner.
5. Lucas is waiting in line right now. / Right now, Lucas is
waiting in line.
6. The cashier is working very hard, but she is a little slow. /
The cashier is a little slow, but she is working very hard.
7. Lucas is looking at his watch because he is thinking about
the time. / Because Lucas is thinking about the time, he is
looking at his watch.
8. Lucas wants to have a great dinner with his cousin.
Activity 14, page 223
Activity 15, page 224
1. coin; A penny is a coin worth $0.01.
2. employer; My company is a really big employer in our town.
3. destroy; A strong storm can destroy houses and buildings.
4. boil; It takes about four or five minutes to boil an egg.
5. points; The arrow points to the location of the exit.
6. choice; For the main course of your dinner, you have a
choice of chicken, fish, or beef.
7. enjoy; Most people do not enjoy movies with sad endings.
8. voice; People want to listen to her songs because she has
an incredible voice.
9. join; I really want to join the basketball team.
10. oil; Many people like oil and vinegar on their salads.
WRITING
Activity 16, page 224–225
Chores
Mr. and Mrs. Hill and their four children live in a very
big house. Their house has five bedrooms, two bathrooms, a
kitchen, a dining room, a huge living room, and a garage.They
do a big cleaning every fall. Mr. Hill cleans the yard. He rakes
the leaves, and he puts them in trash bags.Mrs. Hill cleans all
the outdoor furniture, and their son puts it in the basement.
The oldest daughter mops all the floors in the house, and
the middle daughter washes all the windows. Their youngest
daughter puts away all the summer toys. It is difficult to clean
this big house, so everyone helps.Because everyone does their
job well, the Hill family cleans their house quickly.
Activity 17, page 225
Chores
Mr. and Mrs. Hill and their four children live in a very
big house. Their house has five bedrooms, two bathrooms, a
kitchen, a dining room, a huge living room, and a garage.They
Xare doing a big cleaning today. Mr. Hill is cleaning the yard.
He is raking the leaves, and he is putting them in trash bags.
Mrs. Hill is cleaning all the outdoor furniture, and their son is
putting it in the basement. The oldest daughter is mopping all
the floors in the house, and the middle daughter is washing all
the windows. Their youngest daughter is putting away all the
summer toys. It is difficult to clean this big house, so everyone
is helping.Because everyone is doing their job well, the Hill
family is cleaning their house quickly.
Activity 18, page 225
Answers will vary.
