重点讲解：
1. be late for
迟到；
eg. He was late for school, as was often the case with him.
他上学迟到已是家常便饭了。
eg. I shall be late for lunch, if I stop any longer.
我要再呆下去，吃午饭就来不及了。
2. work out
想出，得到（解决方法）；解（谜）；
eg. We can find a way to work out this problem.
我们可以找到解决这个问题的方法。
eg. I could work out that problem standing on my head.
我解决那个问题易如反掌。
3. at the end
最后；
eg. You'll have the opportunity to ask any questions at the end.
你们最后将有机会提问任何问题。
eg. At the end the old car was practically falling apart.
最后，这辆旧汽车实际上已经要零散了。
