【小站原创】官方真题Official6托福听力Lecture4文本+真题+答案解析

官方真题Official6托福听力Lecture4题目文本

Question 1 of 6

What is the lecture mainly about?

A. an example of rapid climate change.

B. a comparison of two mechanisms of climate change.

C. the weather conditions in the present-day Sahara.

D. recent geological findings made in the Sahara.

Question 2 of 6

Not long ago,the Sahara had a different climate. What evidence does the professor mention to support this?Click on 3 answers.

A. Ancient pollen.

B. Bones from large animals.

C. Rock paintings.

D. Agriculture in ancient Egypt

E. Underground water

Question 3 of 6

In the lecture,what do the Ice Age and the creation of the Sahara Desert both illustrate about past climate changes.Click on 2 answers.

A. that some climate changes benefitted the development of civilization.

B. that some climate changes were not caused by human activity.

C. that some climate change were caused by a decrease of moisture in the atmosphere.

D. that some climate changes were caused by changes in Earth's motion and position.

Question 4 of 6

What started the runway effect that led to the Sahara area of north Africa becoming a desert?

A. the prevailing winds became stronger.

B. the seasonal rains moved to a different area.

C. the vegetation started to die off in large areas.

D. the soil lost its ability to retain rainwater.

Question 5 of 6

The professor mentions a theory that people migrating from the Sahara were important to the development of the Egyptian civilization. Which sentence best describes the professor's attitude toward this theory?

A. It is exciting because it perfectly explains recent archaeological discoveries.

B. It is problematic because it goes too far beyond the generally available data.

C. It raises an interesting possibility and he hopes to see more evidence for it.

D. It cannot be taken seriously until it explains how the migrants got to Egypt.

Question 6 of 6

Why does the professor say this?

A. To correct a misstatement he made about the Sahara's climate.

B. To suggest that the current dryness of the Sahara is exaggerated.

C. To indicate that scientists are not in agreement about the Sahara's past climate.

D. To emphasize the difference between the current and past climates of the Sahara.

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