existence n. 存在 exist on sth. 靠某物生存 There exists …… come into existence 开始存在 【即时巩固】
1.The worker earned little money a month，so he had to________only fast noodles. A．exist on B．exist in C．lie in D．lie on 【答案】A
【解析】考查动词短语意义。句意为：这个工人一个月挣的钱很少，因此不得不靠方便面度日。 exist on靠……生存；exist in存在于……中；lie in在于……；位于……；lie on与……接壤。
2. Earth is a rocky planet where there is liquid water，which is necessary for life to ________.
A．come B．exist C．stand D．happen 【答案】B
考点-4 puzzle vt.vi. (使)迷惑；(使)苦思 n.谜；难题
【教材原句】How life began on earth is one of the biggest puzzles that scientists found hard to solve.
地球上的生命是如何开始的是科学家们一直认为最大的迷团之一。 【例句研读】
(1) Her reply ________ me. 她的回答把我弄糊涂了。
(2) Their reason for doing it is still _______ _______to me. 他们为什麽要做此事我仍莫名其妙。
(3) To explain the ________ findings, he offers two theories. 他提出了两个理论来解释这个令人困惑的发现。
【答案】 (1) puzzled (2) a puzzle (3)puzzling 【拓展归纳】
puzzled adj.无法了解的；困惑的 puzzling adj.令人费解的 sth. puzzles sb. 某事使某人迷惑/为难 到迷惑 sb. be puzzled by sth. 某人对……感
puzzle about/over sth. 对某事感到迷惑或苦苦思索（以便理解） puzzle one’ s brain苦思苦想；绞尽脑汁 solve a puzzle 解决一个难题 【即时巩固】
(1). _______ _______ _______ (使我困惑的事情) is why he left the country without telling anyone.
(2). I _______ _______ (puzzle) that I haven’ t heard from Liz for so long. (3). She listened with a _______ (puzzle) expression on her face.
(4). No one has yet succeeded in explaining the _______ (puzzle) of how life began. 【答案】(1) What puzzles me (2) am puzzled (3) puzzled (4) puzzle 考点-5 pull v.拉，拖，拔；移动 n.拉，拖；拉(引)力
【教材原句】As the rocket rose into the air, we were pushed back into our seats because we were trying to escape the pull of the earth's gravity. 由于我们在努力挣脱地球的引力，我们被向后推在座位上。 【例句研读】
(1) You _____and I’ ll _____. 你来推，我来拉。
(2) . I felt _____ _____ at my sleeve and turned round. 我觉得有人扯我的袖子，便转过身来。
(3) So long as we ______ ______, there’ s no mountain top we can’t conquer. 只要我们齐心协力，没有征服不了的高山。
【答案】(1) push pull (2) a pull (3) pull together 【拓展归纳】
pull ahead (of sb/sth) 领先（於某人/物） 回（某人） pull off (sth)（指机动车辆）驶离（道路）（至路侧停车处停下） pull out (sth.) 拉掉；使分离；掏出；驶离（车站） pull on 穿，戴上（袜子、手套等） 【即时巩固】
1．—Is there any hope of saving his life?
pull together 同心协力；通力合作 pull (sb) back（使某人）退却；撤
—His injuries are extremely serious, but he’s expected to ____. A. pull in B. pull through C. pull up D. pull over 【答案】B
2. ——Is there any hope of saving his life?
——His injuries are extremely serious, but he’s expected to ____. A、pull in B、pull through C、pull up D、pull over 【答案】B
【解析】本题主要考查对短语动词意义的辨析。选项A的意思是“停站，进站，靠岸”；选项B的意思是“恢复健康，度过危机，度过危险”；选项C的意思是“阻止，斥责，使停下”；选项D的意思是“把……拉过来，把……划到对岸去”。根据句子的意思，本题的正确的答案为B。
重点短语精讲
考点-1 in one’s turn轮到某人；接着
【教材原句】Thus they have, in their turn , become the most important animals on the planet.
于是，他们接着成为了这个行星上最重要的动物。 【例句研读】
(1) )The girls called out their names ______ ______. 那些女孩儿逐一报出了自己的名字。
(2) We make every effort to make more films, and ______ ______ this creates further environmental pollution.
我们在竭力生产出更多的电影，反过来这又造成了进一步的环境污染。 (3) We ______ ______ to keep watch. 我们轮流守望
【答案】（1）in turn （2） in turn （3）took turns
【拓展归纳】
in turn依次；轮流；转而；反过来 by turns轮流；交替 take one’s turn轮到某人做……了 take turns依次；轮班，轮流 on the turn正在转变，正在变化 out of turn不合时宜地，鲁莽地 【即时巩固】
1. The waste can be recycled into new products, which _________ will save natural resources.
A. in turn B. in return C. in order D. in time 【答案】A
【解析】短语辨析。A.轮流，依次 B. 作为报答C.整齐 D.及时。句意：废品可以回收利用成新产品，这样（轮流）可以节省自然资源。故选A。
2. The boys is impolite to others and this _________ hurts himself. A. in turn B. at turns C. by turns D. in turns 【答案】A
3．Theory is based on practice and ________ serves practice. A. in turn B. by and by C. by chance 【答案】A
【解析】短语辨析. A.依次;轮流 B. 不久以后C. 意外的 D.既然这样.句意:理论基于实践并反过来为实践服务.结合语境可知选A. 考点-2 prevent...from 阻止；制止
【教材原句】They are putting too much carbon dioxide into the atmosphere, which prevents heat from escaping from the earth into space.
它们把过多的二氧化碳释放到大气层中，这使得地球上的热不能释放到太空中去。
D. in this case
【例句研读】
(1) We must do what we can to prevent pollution _________longer.
我们必须尽力去防止污染为了生活的更长久
(2) The security forces had to intervene to prevent the situation _______
安全部队不得不介入，以防止局势进一步恶化。
(3) Further treatment will prevent the disease _______ developing. 进一步的治疗将阻止疾病恶化。
【答案】(1)to live (2) worsening (3)from 【拓展归纳】
stop sb. (from) doing sth. 阻止某人做某事 keep sb. （from） doing sth. 阻止某人做某事 protect sb. from...保护某人不受……侵袭，挡住，防御 【即时巩固】
（1）Chinese President Hu Jintao called for an immediate ceasefire in Libya________an even worse humanitarian crisis in the country at the BRICS Summit in Hainan Province. A．to prevent B．to have prevented C．preventing D．having prevented 【答案】 A
(2) We must do whatever we can to ________ our environment getting worse and worse. A. separate B. keep C. prevent D. guard 【答案】C
【解析】prevent...(from) doing sth.表示“阻止……做某事”。separate分离，分开；keep sb. doing sth.让某人一直做某事；guard警卫。 考点-3 cheer up 感到高兴；感到振奋 (1)______ ______！ The news isn't too bad. 振作一点吧！也不是什么太坏的消息。
(2)Every time an English runner won a race, the crowd _________.每次英国选手赢得赛跑冠军，观众就欢呼。