重点讲解：
1. in an attempt to do sth. 试图（做）；
例句：Mrs Watson fell all over her distinguished guest in an attempt to make him completely comfortable.
沃森太太对她的贵宾殷勤备至，力求让他感到十分舒适nW*5TsM4Q^。
2. be aimed at 旨在；目的是；
例句：Much of his effort is aimed at deterring his rival from intervening in a future crisis over his business.
他的大部分努力旨在阻止将来竞争对手的介入给他的生意造成危机Bj*cm+08g]Vm5。
3. step up 增加（数量等）；提高（速度、强度等）；
例句：If the medicine has little effect after a week, step up the quantity.
1周后这药不见效，再加量nbVPE%9eG4N#hB。
4. account for （数量或比例上）占；
例句：Drug costs account for a higher proportion of the total medical costs.
药品费用占医疗总费用比例较高jRH-YM[]BNqu。
5. in conjunction with 连同…；与…一起；
例句：She opened a store in conjunction with her friend.
她和朋友合开了一家店Fxp8!RS(Gw8)Zy0vMhJ@。
6. serve as 用作；可当…使用；充作；
例句：We found that birch bark could serve as paper.
我们发现桦树皮可以作纸用4k]&%^zX!K。