高中(人教)英语选修9课件：unit 5 section 2

Module 2 DNA—the Secret of Life

Currently there are some 20,000 chemicals in use, but the

scientists only have detailed information on around 1,000 of

them.To see the advantages of GM food you have only to

consider the recent press revelation that the average lettuce

receives eleven pesticide applications before it reaches the supermarket shelf.I'm sure

chemicals and their roles in disease will become a big issue in the next century as the

population of the developed world worries increasingly about its health.

The reason GM food will not go away is that we need a three-fold increase in food

production by the year 2050 to keep pace with the world's predicted population growth

to ten or eleven billion.It's not just a question of more mouths to feed either.What is

often forgotten is that all these extra people will take up space, reducing the overall land

Unit 5 Section Ⅱ

Ⅰ.单句语法填空

1.（2016·江苏卷改编）Dashan, who has been learning （ learn）

crosstalk, the Chinese comedic tradition, for decades, wants to mix it up

with the Western stand-up tradition.

解析：考查动词时态。句意：大山，多年来一直学习中国传统的喜剧相声，想把西方的单口表演与中国相声相结合。题干中有for decades，强调学习的动作从过去某个时间开始，一直持续到现在，并有持续下去的趋势。故用现在完成进行时。

2.（2016·浙江卷改编） Silk had become (become) one of the primary

goods traded along the Silk Road by about 100 BC.

解析：考查动词时态。句意：大约公元前100年，丝绸已经成为丝绸之路上最主要的交易商品之一。根据句意以及by about 100 BC可知，强调过去的过去的动作，故用过去完成时。

3. The students have been working (work) hard on their lessons and

their efforts will be rewarded success in the end.

解析：考查动词时态。句意：学生们一直在努力学习，他们的付出最终会获得成功的。根据题干可知，强调work的动作一直进行，故用现在完成进行时。

4.Over the past ten years, the sea level has been rising (rise) as a result

of global warming.

解析：考查动词时态。句意：由于全球变暖，在过去的十年中，海平面一直在上升。根据题意可知，rise动作从过去某个时间开始，一直持续到现在，并有持续下去的趋势。故用现在完成进行时。

Ⅰ.单词拼写

1．What criteria (标准) are used for assessing a student's ability?

2．He seized (抓住) her by the arm all of sudden.

3．He applied for a patent (专利证书) for a new method of removing paint.

4．TV does have lots of advantages, but on the other hand, it makes people passive (被动的) and lazy.

5．Their products (产品) are of high quality and are popular with many customers.

6．Those tomatoes aren't ripe (熟的) yet. You'd better not eat them.

7．The man said that my passport wasn't valid (有效的) and didn't allow me to go abroad.

8．They were so much alike that we could hardly distinguish (辨别) one from the other.

Ⅱ.拓展词汇

1．mercy n．慈爱→merciful adj.慈爱的→merciless adj.无情的

2．abrupt adj.突然的；意外的→abruptly adv.突然地；唐突地

3．convenient adj.便利的；便利的；就近的→convenience n．便利；便利→conveniently adv.便利地；便利地

4．caution n．当心；谨慎→cautious adj.当心的；谨慎的

5．expectation n．预料；期盼；期望→expect v．预料；期盼；期望；认为

Section_ⅡWarming Up & Reading — Language Points

1．approximate adj.近似的，大概的

What is the approximate number of students in each class?

每个班大致有多少学生？

be approximate to 接近

approximately adv. 大约；近似地

Your story is approximate to the real facts.

你所说的接近事实真相。

The journey took approximately seven hours.

旅行大约用了七个小时。

[即境活用1]

完成句子

(1) 他们的日常花费一月大约2 000元。

Their daily cost is_approximate_to 2,000 yuan a month.

(2)飞机大约在20分钟后着陆。

The plane will be landing in_approximately_20_minutes.

2．reality n．真实，实在；事实；逼真，活现

He doubted the reality of what he had seen, thinking he must have dreamed it.

他不相信自己所见到的是真的，以为自己一定是在做梦。

It is sometimes hard to face reality.

有时很难面对现实。

in reality (＝in fact) 事实上，实际上

with reality

真实地，逼真地

She seemed confident but in reality she felt extremely nervous.

她看起来信心十足，而实际上她紧张得要命。

[即境活用2] 完成句子

(1)他可以把所有的事情都描绘得活灵活现。