重点讲解：
1. have to do sth.
需要；必须；不得不；
eg. He will have to mortgage his land for a loan.
他不得不将土地抵押来申请贷款。
eg. You have to come to terms with reality.
你必须接受现实。
2. go to bed
上床睡觉；
eg. I go to bed round 11:00 at night.
我大约晚上11点上床睡觉。
eg. It is the time you should go to bed.
你该去睡觉了。
3. talk about
讨论；谈论；
eg. If you don't mind, we won't talk about it any more.
如果可以的话，我们就不要再谈论这件事情了。
eg. Please don't talk about it in front of the children.
请不要当着孩子们谈论那事。