重点讲解：
1. pay off 成功；赢利；
例句：Sandra was determined to become a doctor and her persistence paid off.
桑德拉决心成为医生，她的坚持取得了成功yRNR*(hjO^K.。
2. on average 平均起来；按平均值；
例句：Researchers found that Britons work an additional 460 hours a year on average as they are able to respond to emails on their mobiles.
调查人员发现，由于可以随时用手机查收电邮，英国人每年的工作时间平均增加了460个小时,JoVoU|[CJE.l15。
3. no matter 不管…；无论…；
例句：No matter how hard he tried, I still have no visualization of his design.
无论他怎么努力说明，我还是想像不出他的设计到底是什麽样子DmQb[o,YGitr。
4. even if 即使；尽管；纵然；
例句：Don't fail to do good even if it is small.
不要因善小而不为t%~_0Cg#y8m,LlkMpC。