重点讲解：
1. down on one's luck （常指因缺钱而）遭遇厄运，时运不济；
George has certainly been down on his luck recently, first his wife fell ill, then he lost his job.
乔治近来真倒霉，先是他妻子病倒了，之后他又失业了。
2. encourage sb. to do sth. 鼓励；激励；
It would be irresponsible of me to encourage you to invest in the poorly managed company.
如果我鼓励你投资于该管理不善的公司，那是不负责任。
3. count up 计算(或清点)总数；
I must count up how much money I've spent today.
我得算一下今天我总共花了多少钱。
4. buy back 买回；
He will buy back his property.
他将把自己的财产买回来。