重点讲解：
1. what if
（用于疑问句句首，尤用于询问不希望看到的事发生时的结果）如果…怎么办；
eg. What if this doesn't work out?...
如果这个不行怎么办？
eg. What if relations between you and your neighbour have reached deadlock, and their behaviour is still unacceptable?
如果你和你的邻居已闹僵了，而他们的行为还是令人难以接受，那怎么办？
2. waste time (in) doing sth.

浪费时间做某事；
eg. There could be many reasons and he was not going to waste time speculating on them.
原因可能有很多，他不打算浪费时间对此妄加猜测。
eg. Don't waste time thinking back to what you could have done differently yesterday.
不要浪费时间去想若是回到昨天你就可以做得更好。
3. an awful lot
（量）极大的，极多的；
eg. I've got an awful lot of work to do.
我有一大堆事情要做。
eg. We're having an awful lot of rain these days.
这些日子尽下雨。