4  OUR CHANGING PLANET

THINK AND DISCUSS (page 61)

Possible answers:

1. A good way to describe this place would be as wild but peaceful. It looks like somewhere that has not been affected by human activity. It is a mountain range with high rocky peaks. There is a valley, and a

river in front of it. There is also forest.

2. The mountains are likely to be reduced in height because of the effects of wind, rain, and snow. Where the river flows might have changed. Humans might have cut down some or all of the trees. It is even possible that people might have built a town or city in this area.

EXPLORE THE THEME (page 62)

1. Answers will vary.

2. Possible answers: People visit the park to see the unusual sights, to see wildlife, to experience nature.

3. Answers will vary.

Lesson A

VOCABULARY

A (page 64) Answers will vary.

B (pages 64–65)

1. appropriate

2. unique

3. dramatic

4. exposed

5. crack

6. pressure

7. formation

8. landscape

9. erode

10. collapse

C (page 65)

1. Answers will vary.

2. Possible answers: The natural action of gravity can cause erosion by, for example, causing rocks to fall onto other landforms. Human actions such as walking, riding bikes, or driving cars might also erode a landscape. Heat from the sun can dry the soil and kill plants, which could lead to erosion of the soil.

3. Answers will vary.

4. Possible answers: Water can be under pressure in a bottle. It can also be under pressure in a pressure cooker. When the pressure is released,

the water often comes out quickly and powerfully.

5. Possible answer: People might continue to use a plate, a cup, a cell phone, a mirror, or something plastic that has a crack in it.

6. Answers will vary.

D (page 65)

1. b; 2. a; 3. b; 4. c; 5. b; 6. a

LISTENING

A (page 66) Answers will vary.

B (page 66)

Possible answer: A geology professor described the formation of karst landscapes in general and then discussed one specific example of a karst

landscape.

C (page 66)

1. f; 2. d; 3. b; 4. e; 5. a; 6. c

D (page 67)

Digressions:

Interestingly, the term limestone doesn’t come from the color of the rock, which is typically white or gray, not green, but from lime, an important industrial product made from limestone.

Uh, we usually think of acid rain as being caused by human industry, but sometimes acid rain can be caused by gases from volcanoes.

Words that signal a return to the main point:

Anyway, limestone is a relatively hard rock, but water

can wash it away, especially water that is slightly acidic.

Now as I was saying, water can erode limestone.

E (page 67)

1. KP; 2. D; 3. D; 4. KP; 5. D

F (page 67)

1. Answers will vary.

2. An advantage for a speaker can be that a digression can be a way of adding some especially interesting information or something

humorous. A disadvantage is that it can use up time and may not be directly related to the topic.

SPEAKING

A (page 68)

The eruption of Mount Vesuvius in AD 79 is one of the most famous in history. Two Roman towns were destroyed and numerous citizens were killed. The eruption was observed by the writer Pliny the Younger. He described the eruption in two letters to Tacitus, another famous Roman. His description was so detailed and accurate that similar eruptions are called Plinian by modern geologists. These days the sites of the destroyed towns are often visited by tourists. However, this may not be a safe thing to do as Vesuvius is considered to be an extremely dangerous volcano by many experts.

B (page 69) Possible questions:

Which two towns were destroyed by Vesuvius? How many citizens were killed by Vesuvius? Where was Pliny the Younger when he observed the eruption? What was Tacitus famous for? What can tourists see at the sites of the destroyed towns? Why is Vesuvius considered dangerous by experts?

C (page 69) Answers will vary.

D (pages 69–70)

Student A notes

1. They are a Native American tribe.

2. The “Legend People” originally lived there.

3. They were turned to stone for being bad.

4. It is called “Red Painted Faces” by some tribe members.

Student B notes

1. They can be called tent rocks or earth pyramids.

2. They have a layer of hard rock on a thicker layer of soft rock.

3. They are formed when the softer rock is eroded

by the weather.

4. The park is located in Utah, and it is special

because more hoodoos are found there than

anywhere else.

E (page 70) Answers will vary.

LESSON TASK

A–B (page 71) Answers will vary.

Video

A (page 72) Answers will vary.

B (page 73) Answers will vary. See exercise E for the correct answers.

C (page 73)

1. g; 2. a; 3. b; 4. f; 5. d; 6. c; 7. e

D (page 73)

1. a; 2. c

E (page 73)

1. False (The Colorado River has existed for 6 million years.)

2. True

3. False (It is not the strongest or largest river in the United States.)

4. True

F (page 73)

1. The best answer is a. In fact, the name of the Colorado River comes from a Spanish word meaning colored, especially red or reddish.

2. Answers will vary.

3. Answers will vary.

Lesson B

VOCABULARY

A (page 74)

1. c; 2. a; 3. b; 4. b; 5. c; 6. b; 7. a; 8. a; 9. a; 10. c

B (page 75)

1. find / get

2. between

3. major

4. on

5. countable

6. reach / come to

7. cause / suffer

8. to

9. of

10. carry out / perform

C (page 75) Answers will vary.

LISTENING

A (page 76)

Possible answers: price, location, quality of education, size, course offerings, reputation

B (page 76)

• location

• available majors

• tuition cost

C (page 76)

1. 3 / three

2. ecotourism

3. air travel

4. New York (University)

5. 2 / two

6. Canada / Mount Royal (University) / Calgary

D (page 77) Possible answers:

1. Ecotourism is the idea that people’s vacations should cause as little damage to the environment as possible.

2. How to carry out an analysis of the tourist area; how to work with community members to make tourist practices locally sustainable; what kind of infrastructure is least harmful for the environment

3. You could do research online or attend a course at a local college or university.

E (page 77)

1. Possible answer: Natural Hawaii sounds more like an ecotourism vacation because the description mentions things like “minimize the impact of all activities,” “environmentally-friendly lodge,” and

“visit Hawaii without changing it.”

2. Possible answer: Active Hawaii sounds like it might be more expensive because the hotel is five-star and modern. Also, the activities may be

expensive as they may require renting equipment such as mountain bikes, diving gear, and a boat. Natural Hawaii may be less expensive if the meals are prepared with seasonal local ingredients, and an environmentally-friendly lodge likely requires less energy to run than a modern hotel.

3. Answers will vary.

SPEAKING

A (page 78) Answers will vary.

B (page 79) Answers will vary.

FINAL TASK

A (page 79) Answers will vary.

B (page 79) Possible answers:

Neutral – online encyclopedia, newspaper website

Up-to-Date – online encyclopedia, newspaper website

Accurate – online encyclopedia, newspaper website

Biased – personal blog post

Out-of-Date – personal blog post

Inaccurate – personal blog post

C–D (page 80) Answers will vary.