重点讲解：
1. close off 隔绝；封锁；
例句：Police closed off about 12 blocks of a major San Francisco thoroughfare for today's march.
由于今天的示威游行，警方封锁了旧金山一条主干道上大约12个街区%[[;V;hgjWbuOWr]_eq。
2. so as to do sth. （用于引出原因）为了；以便；
例句：You should exercise more so as to keep energetic.
你应当多锻炼以保持精力充沛jx@(J#-[skZcaPa^Nr2。
3. cut down 砍倒（树木）；
例句：A vandal with a chainsaw cut down a tree.
一个故意破坏公物的人用链锯伐倒了一棵树5diT[JK@Y[O;nx&*h!X。
4. suffer from （因疾病或处于其他不利境地而）受苦，受难，受折磨；
例句：Many kids suffer from acne and angst.
许多年轻人都会受到青春痘和焦虑的困扰2CVb9&;Wd.Kic@]3。
5. make up 组成；构成；
例句：Women officers make up 13 per cent of the police force.
女警占警力的13%C%7tz5R*]E5Si。
6. 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TVq^%c@Gp!8I-)A;。
7. in an effort to do sth. 为了做某事；努力做某事；
例句：She has been studying very hard in an effort to catch up with her classmates.
她学得非常努力，以便赶上她的同学+!omht+6kya+。
8. break up （使）分裂；（被）拆分；（使）破碎；散（会）；（使）解散；
例句：Police tried to break up the gang.
警察试图瓦解黑帮YMr5xbggSG,Z6_PF)。