最新人教版选修8高中英语过关习题BOOK 8 Unit 2 Cloning及答案

人教版高中英语达标习题

Ⅰ.阅读理解

(2012·广东潮州月考)The hole in the Earth's ozone layer (臭氧层)has until now protected Antarctica from the worst effects of global warming.But scientists have warned that as the hole closes up in the next few decades，temperatures on the continent could rise by around 3℃ on average，with melting ice contributing to a global sea level increase of up to 1.4 metres.

In the past decades the western Antarctic has seen rapid ice loss as the world has warmed，but the other parts of the continent have，paradoxically，been cooling，resulting in a 10% increase in ice in the seas around the region.This is because the hole in the ozone layer has increased cold winds in Antarctica，making much of the continent surface colder than usual.

But now that the gasses that cause the ozone hole have been banned，scientists expect the hole to repair itself within the next 50 to 60 years.By then the cooling effect will have faded out and the Antarctic will face the full impact of global warming.This means an increase in average ai r temperatures of around 3℃ and a reduction in sea ice by around a third.

The biggest threat to the continent comes from warming seas.Robert Johnson，a scientist who monitors Antarctica ice sheets，said，“The ice sheets in Antarctica are hundreds of metres thick.But once warm ocean waters start flowing underneath，the ice will begin thinning and could break up very quickly.” Thinning ice sheets cause ice to break away from the continent and to melt even faster.Escaping ice from western Antarctica has already resulted in a 10% rise in global sea level in recent decades.

Johnson believes that international action to reduce global warming

is required immediately or it may be too late.“Everything is connected—Antarctica may be a long way away but it is an important part of the Earth's system，” said Johnson.“It contains 90% of the world's ice,70% of the world's fresh water and that is enough，if it melts completely，to raise sea levels by 63 metres.”

Even in a worse­case situation scientists don't expect the ice to entirely disappear，but predict that，because of the melting ice sheets，average sea level rise will be around 1.4 metres higher by the end of the century.

【语篇解读】本文主要描述了由于臭氧层的破坏，南极洲冰层正处于加速融化的危险中。科学家认为南极冰层不会完全消失，但海平面会随着冰层的融化而上升。

1．The underlined word “paradoxically” (in Paragraph 2) most probably means “________”．

A．rapidly B．approximately

C．contradictorily D．apparently

【解析】词义猜测题。首先，选项词义要牢记；其次，划线词所在句中的but为推断关键，划线词应理解为相反地。

【答案】 C

2．What is the effect of the hole in the ozone layer on Antarctica?

A．It is making much of the continent colder.

B．It is causing the ice to melt faster.

C．It is making the effects of global warming in the region worse.

D．It is reducing the amount of water in Antarctica.

【解析】细节理解题。从第二段最后一句“This is because the hole in the ozone layer has increased cold winds in Antarctica，making much of the continent surface colder than usual.”可以得出答案。

【答案】 A

3．What do scientists think is the biggest danger facing Antarctica?