collapse 塌陷; 倒塌
*The roof of the tunnel fell in. 隧道顶部塌了下来. fall (sb) in (cause sb to) form a military formation; (cause sb to) go on parade （使某人）排成军事队形; （使某人）集合
*The sergeant ordered his men to fall in 中士命令士兵集合. fall in with sb/sth
(a) meet sb by chance; join sb; become involved with sb/sth 偶遇某人; 与某人在一起; 与某人[某事物]牵涉在一起
*He fell in with bad company. 他交上了损友.
(b) agree to or show support for sb/sth 同意或支持（某人[某事物]）
*She fell in with my idea at once. 她立即同意了我的意见.
1. Why does a person standing in a bus or train tend to fall when a sudden start is made? 一个人站在公共汽车或火车上，当车突然开动时，他为什么会倾倒呢？
2. These fall into the same category. 这些独成一类。
3. These matters fall within/go beyond the cognizance of this court. 这些问题在本法庭审理范围之内(外).
4. The bush acted as a cushion to my fall. 灌木在我摔下时起了缓冲作用。
5. The fall of the river here is two feet. 此地的河水降落两英尺。
6. The day of retribution shall fall upon him. 他遭报应的一天就会到来。
7. The seeds must be carefully chosen; they must fall on good ground; they must be sedulously tended, if the vivifying fruits are to be at hand when needed. 要想在需要的时候可随手摘取充满生机的果实，那就必然从选良种做起，然后将其植入肥沃的土地，还需要勤勉地护理。
8. There are plenty of high-rise windowsills to fall from! 有的是高层的窗槛从上往下坠落。
9. They feared that the mummy would fall to pieces when they cut it open, but fortunately this has not happened. 他们曾担心在把木乃伊切开后，它会散成碎片，但幸运得很，这种情况并未发生。
10. The heavy raids began in the middle of August, and Nazi bombs started to fall along England's Channel Coast. 猛烈的空袭是在8月中旬开始的，纳粹的炸弹开始落在英吉利海峡的海岸线上。