Man wants to explore deep into the sea.However, he is not a fish.He must breathe air, so he can't stay under the water's surface for any length of time.To explore deep water, man faces even more dangers and problems.
A diver who wants to stay under water for more than a few minutes must breathe air or a special mixture of gases.He can wear a diving suit and have air pumped to him from above.He can carry a tank of air on his back and breathe through a nose and a mouthpiece.Water weighs 800 times as much as air.Tons of water pushes against a diver deep in the sea.His body is under great pressure.
When a diver is under great pressure, his blood takes in some of the gases he breathes.As he rises to surface, the water pressure becomes less.If the diver rises too quickly, the gases in his blood form bubbles.The diver is then suffering from the bends.The bends can cause a diver to double up in pain.They can even kill him.
20.On the whole, this passage is about ________.
A.special mixtures of gases in deep sea
B.the problems man faces in deepsea diving
C.air pressure under the surface of sea water
D.a kind of illness that man suffers in the sea
21.The passage does not say so, but it makes you think that ________.
A.deepdivers should be in good health
B.divers explore the deep sea only for treasure
【2017届高考英语一轮复习课时作业33:Unit 3《Under the sea》(新人教版选修7福建专用)】相关文章:
★ 【人教版】2014届高考英语一轮复习指导考点针对练:必修4 unit1《Women of achievement》
★ 【人教版】2014届高考英语一轮复习指导考点针对练:必修5 unit1《Great scientists》
★ 【浙江专用】2014届高考英语一轮复习课时作业(二十八)选修6Unit 3《A healthy life》
★ (安徽专用)2014届高考英语一轮复习方案 作业手册(11)模块4 《Unit 11 The Media》(含解析) 北师大版必修1
★ 四川省2016届高考英语一轮复习课时作业(36) Module 6 War and Peacel 外研版选修6
★ 2017届江苏省淮安市新马中学高考牛津译林版英语一轮复习活动单:模块7 unit 4《Public transport》
★ 四川省2016届高考英语一轮复习课时作业(45) Module 3 Foreign Food 外研版选修8
★ 四川省2016届高考英语一轮复习课时作业(39) Module 3 Literature 外研版选修8
★ 2017届江苏省淮安市新马中学高考牛津译林版英语一轮复习活动单:模块7 unit 1《Living with technology》
★ 北京市2014高考英语一轮复习 练习手册(40)选修8 Unit 5 Meeting your ancestors(含解析)新人教版
最新
2017-04-24
2017-04-24
2017-04-24
2017-04-24
2017-04-21
2017-04-21