Why does a rock avalanche move faster than other types of rockslides？
A．The rock moves over a layer of compressed air.
B．The rainfall is heavy where avalanches occur.
C．The rock breaks apart as it moves downslope.
D．The angle of the slope is almost vertical.

A．It was cold.
B．It was a failure.
C．I'm very happy.
D．She is shy enough.

听力原文：We're going to look around the city tomorrow morning.
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A．I'll try my best to do it.
B．I'm looking forward to that.
C．I feel a little cold in the morning.
D．I haven't eaten my breakfast yet.

Why does the professor say this:
A．He is showing the students some slides.
B．He does not want the students to ask questions.
C．He wants the students to pay attention.
D．He thinks that the information is very clear.

Why are bacteria being used in the research study at the university？
A．Bacteria have unusual cell formations.
B．Bacteria live harmlessly on the skin.
C．Bacteria are similar to other life forms.
D．Bacteria cause many diseases in humans.

Where would this passage most likely appear？
A．In a magazine specifically for women.
B．In a restaurant and hotel guide.
C．In a news magazine.
D．In a journal for top-ranking businessmen and women.