重点讲解：
1. was/were supposed to do sth. 本应该做某事；
例句：Wells was supposed to put up half the money, but later backed out.
韦尔斯本应当出一半的钱，但后来他食言了@ddW|i951y。
2. take off 动身；出发；
例句：Let's take off in an hour.
我们一小时后出发l;wlv,u[khDODk@p4。
3. rip off 敲…的竹杠；对…漫天要价；坑骗；
例句：The airlines have been accused of ripping off customers.
这家航空公司遭到向顾客漫天要价的指责w~JeO+;@K#++2s。
4. take advantage of 利用；占…的便宜；
例句：I took advantage of his weakness.
我利用了他的弱点66gA0xAGVTj。