1.fall apart 破碎，破裂
例句：But having a strong and honest kind of relationship will it fall apart.
一個堅強的和誠實的感情關系將會破碎。
2.fall asleep 入睡，長眠，死
例句：He started to fall asleep; I knew he was exhausted so I stroked his hair and watched him.
他睡著了,我知道他太累了,于是我輕輕地撫摸著他的頭發,看著他。
3.fall back on 借助于,依靠，撤退到
例句：Doctors sometimes fall back on old cures.
醫生們有時求助于傳統療法。
4.fall behind 落在后面
例句：They charge lower upfront fees than other cards do. But if you fall behind, it's tough.
他們比其他卡收取的預支費要低，但是如果你拖欠還款，那就日子艱難了。
5.fail to do sth 做某事失敗
例句：Many people fail to do this and wonder why they cannot concentrate.
很多人做不到這一點，并想知道為什么他們不能全神貫注。
6.fall down 跌倒，摔倒，失敗，未能符合要求
例句：There's nothing to be afraid of. The sky won't fall down.
沒有什么好怕的， 天不會塌下來。