17.
W: Thank goodness, you're back. How is our car? Were you injured?
M: The mechanic said that the best thing would be to sell it and buy a new car. This car is totally dead.
Q: What do we know from the conversation?
正确答案： C
解析：男士说“最好是卖了它再买辆新车”，可判断C（车该换了）为正确答案。C中的replaced即是sell it and buy a new car的同义替换。

18.
W: Why do the Japanese have such a long life expectancy?
M: I don't understand. So many of them smoke, and they have a stressful work environment. It must be their healthy diet. Hey! Let's go out for sushi!
Q: What does the man suppose contributes to the Japanese long life expectancy?
正确答案：C
解析：女士问为什么日本人平均（预期）寿命这么长，男士先说不清楚，后又猜测说：“那一定是因为他们的健康饮食的缘故”。C是原文diet的同义表达，故C正确。