Unit 3 Life in the future
previous, lack, switch, take up, lose sight of, speed up, as though
1. previous adj. 以前的；早先的
previous to 在…前；先于…（to为介词）
previously adv. 以前地；先前地
eg: No previous experience is necessary for this job.
Previous to this, she’d always been ill.
The world record was previously held by a Spanish athlete.
2. lack v.&n. 缺乏；缺少的东西
1 v.
lack for + n. （多用于否定句中）需求；需要
2 n. a lack of + n. 缺乏…
no lack of 不缺乏
3 lacking adj. 短缺的；缺乏的
be lacking in 缺少
eg: Li Jiawei’s real problem is that she lacks confidence.
He has got a bad headache through lack of sleep.
The film was lacking in pace.
3. switch n. 开关；转换 vt. 转换
switch on 接上；打开
switch to 变换到
switch off 切断；关掉
switch over 完全转变；转换
make a switch 进行改变
eg: Which switch do I press to turn it off?
He switched the light on.
Hold on, please. I’ll switch you to the manager.
We had to make a switch in our arrangement.
Lucy returned home from work early. After changing clothes, she switched off the light and came downstairs. Then she switched on the TV and switched over with boredom.
4. take up 拿起；接受；开始；继续；占据
take apart 拆开（机器）等
take away 拿走，夺去
take back 收回（说错的话）
take down 取下；记下；拆卸
take for 认为，以为；误认为
take in 接受，吸收；包括；领会；欺骗
take on 承担；呈现；开始雇用
take off 拿走；脱下（衣帽等）；起飞
take over 占据；接任（职位）
take out 拿出；去掉；扣除
eg: She took up her first teaching post in 2009.
The runners took up their positions on the starting line.
Is the supermarket taking on any more assistants?
He is taking over my job while I am on holiday.
5. lose sight of 看不见
at the sight of… 在看到…时
catch sight of… 望见，看到…
in / within sight 在视线内，可以被看见
in sight of… 可以看见…
out of sight 看不见了，不被人看见
eg: I lost sight of him in the crowd.
She let out a cry at the sight of the snake.
Sheila caught sight of her own face in one of the shop windows.
When we got to the beach, there wasn’t a soul in sight.
6. speed up 加速
at high / low / full / top speed 以高 / 低 / 全 / 最高速
at a speed of… 以…速度
with all speed 尽快地
reduce speed 减速
pick up speed 加速
eg: We’d better speed up if we want to be in time for the film.
At the turning, the car reduced speed.
The police car is running at a speed of 100 miles per hour to chase after the truck ahead of it.
7. The air seemed thin, as though its combination of gases had little oxygen left.
as though = as if“似乎是，好像是”，其后可接分词、过去分词、不定式、形容词、副词、介词短语、名词。
as though的意义和用法与as if相同，用来引导方式状语从句，如果从句表示的情况是事实，使用陈述语气，主句的位于多为look，seem，taste，smell，sound等词；如果从句表示的情况不是事实，则用虚拟语气，形式如下：
1 从句的动词在时间上与主句动词同时发生，从句的动词用过去时。
2 从句的动词在时间上先于主句的动词发生，从句的动词用had done。
3 从句的动词在时间上比主句的动词晚发生，从句的动词用would / could / might + do。
eg: It looks as though they have succeeded in the experiment.
She talks about
The boy is running here and there as though searching for something.
The old man set upon the thief as though mad.
8. Hit by a lack of fresh air, my head ached.
1 过去分词作状语时与主语的关系：若其逻辑主语是句子的主语，则与句中主语含有逻辑上的被动关系。
2 过去分词的句法功能：可以在句中作时间、原因、方式、条件、让步等状语。
3 过去分词的独立结构：过去分词作状语时，若其逻辑主语不是句子的主语，则须在过去分词前加上自己的逻辑主语，构成独立主格结构。
4 过去分词作状语的位置：多放在句首，也可放在后面或插在中间，一般要用逗号同其他部分隔开。
eg: Dealt with in a proper way, waste can be turned into useful things.
United, we stand; divided, we fall. (= If we are united, we stand; if we are divided, we fall.)
The table set, they began to dine.
He stood there silently, moved to tears.
练习：
用previous的正确形式填空
1. She has two children from a marriage.
2. It was time to interview the farmer, for whom I had
worked.
3. to her departure, she gave a big party.
4. Though money, his parents managed to send him to university.
A. lacked B. lacking of C. lacking D. lacked in
5. He used to play tennis, but now he has (改变，转变) golf.
6. He got tired of teaching and (转而) writing stories.
7. ---It doesn’t work.
---Have you (打开它)?
8. As the holiday is drawing near, tourism is starting to
.
A. run off B. go off C. take off D. break off
9. My study of biology has much of my spare time, but it has given me a great deal of enjoyment.
A. taken in B. taken down
C. taken up D. taken away
10. After having followed the thief for half an hour, they him in a large department store.
A. lost the sight B. caught sight
C. out of sight D. lost sight of
11. 火车以每小时
The train runs 200 kilometres an hour.
12. 他们加快了新汽车的生产。
They have production of the new car.
13. He often speaks too much as though he
everything.
A. knows B. had known
C. knew D. has known
14. She had a tense expression on her face, she was expecting trouble.
A. even though B. as though
C. so that D. now that
15. The best part to Peter, John was so disappointed that he felt unwilling to continue his taking part in the play.
A. given B. giving C. to give D. having given
16. in a traffic jam, students of a college in
A. Having caught B. Be caught
C. Being caught D. Caught
Unit 3 Life in the future
1. previous 2. previously 3. Previous 4. C 5. switched to 6. switched to 7. switched it on
8—10 CCD 11. at a speed of 12. sped up 13—16 CBAD
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