A、An earthquake. B、A volcano. C、A landside. D、A warm current. D

M: Hi, mom, what are we having for dinner tonight?
W: I haven’t started yet. Why, have you any requests?
M: (9) How about tsunami for a change — I don’t know what it is, but I heard some Japanese people using the word on the bus the other day. Sounds like a food.（ 男孩问妈妈晚饭吃什么，要求妈妈做 tsunami来换个口味，他虽然不知道那是什么，但是听起来像食物。）Maybe it’s similar to sushi.
W: Nonsense. Tsunami comes from Japanese words meaning harbor and wave. If we had a tsunami, it would be the other way around, young man.
M: Why? What is it?
W: (10) I mean it could swallow you up.（母亲说如果吃了海啸，它会把你吞噬的。） A tsunami is an enormous series of very powerful waves.
M: ( 11) Could you surf on them? That could be cool!（ 男孩认为在海啸上冲浪很酷。）
W: They’re not cool. They are very destructive. When they pound the shores of populated areas, they cause tremendous damage. They destroy everything in their path.
M: What causes them?
W: (12) I think they are caused by some sort of shock, like an earthquake, volcano, or landslide, that starts a chain reaction in the ocean.（引起海啸的因素有地震，火山喷发，泥石流等，它们在海底引起了一系列的连锁反应。）
M: Do the waves get so big that they crush buildings?
W: Easily. They can be dozens of meters high. They toss cars and houses around as though they were children’s toys.
M: Can you see them coming?
W: You can see them at quite a distance. But there’s not much you can do. In the ocean they move at up to 800 km per hour, but when it reaches the shore, the system slows down and the waves get bigger.
M: How big?
W: They can reach 30 meters. Big enough to finish you off in one gulp.
Questions 9 to 12 are based on the conversation you have just heard.
9. What does the son think a tsunami is?
10. What does Mom imply by saying, “If we had a tsunami, it would be the other way around”?
11. What does the son think surfing on tsunami waves would be like?
12. Which of the following is not mentioned as the cause of a tsunami?