即时训练
Ⅰ.单词拼写
1．The drug is effective but has a tendency(倾向) to cau headaches.
2．There was widespread (普遍的) support for the war.
3．On the whole (大体上)，I thought the film was pretty good.
4．The average (平均的) cost of making a movie has rin by 15%.
5．On behalf of (代表……一方) everyone here，may I wish you a very happy retirement?
6．Prisoners can only leave their cells under certain circumstances(情况)．
7．He refreshed (使振作) himlf with a glass of iced tea.
8．The fire was caud by an electrical (与电有关的) fault.
9．Einstein was awarded the Nobel Prize for his contributions(贡献) to Quantum Theory.
10．We've had a few disagreements(分歧)，but we're still good friends.
Ⅱ.单句语法填空
1．I am in ________(disagree) with him over whether we should buy large quantities of fuels at a time.
2．There is a growing ________(tend)towards having two children in our country.
3．Every one of us can make a ________(contribute)to our class if you make an effort.
4．What the ________(educate)stated in his report is not entirely right.
5．I just can't put up with air and water ________(pollute)．
6．He made a ________(commit)to himlf that he would never show any prejudice towards cleaning women.
7．Breathing in some fresh air in the morning can ________(fresh)ourlves.
8．There is no doubt that every parent would like to e their kid's ________(grow)．
9．It is not appropriate to wear so ________(casual)on such a formal occasion.
10．It is clearly stated in the book when the tradition came into ________(exist)．
答案：1.disagreement 2.tendency 3.contribution
4．educator 5.pollution 6.commitment 7.refresh 8.growth 9.casually 10.existence
Ⅲ.阅读理解
Polar bears are dying out! They are dying becau they are losing a great deal of habitat due to human incursion (侵入) and global warming. They are dying becau of starvation as well. With the a ice they depend on for survival shrinking(缩小)，it is becoming increasingly difficult for them to find food.
An ecosystem is highly dependent on all of its parts，and removing even a single specie
s can result in rious conquences.Polar bears are at the top of the predators (捕食性动物) where they live.They play an important part in the ecosystem.They feed on als，fish and deer.Several other carnivores depend on the kill of polar bears.The failure to save polar bears might result in loss of the predators.
In addition, all large predators perform a very important function in their habitat: helping to control the populations of other species.When an animal group los its natural predators，its population will ri rapidly，having a direct result in population decrea of other groups.A huge boom in population of Arctic als would have a direct effect on the prey of als，and could reduce numbers of certain types of fish.
This could also have a direct effect on humans，who might have to compete with Arctic als for food supplies from fish. Lack of polar bears could eventually affect human food supply.Human beings shall save polar bears to ensure the food supply.
There is no doubt that we should save polar bears.However，there is still another question: can they be saved? This is a matter that scientists debate becau of rapid deg
radation (恶化) of the polar bears' environment in recent years due to warming temperatures. It is estimated that if the bears cannot adapt to changing climates，they might die out before the end of the 21st century，with about 50% of the animals disappearing by 2050.So time is running out!
There are some things that may help slow down global warming and help delay extinction (灭绝) of polar bears. The include finding new energy sources that don't give off greenhou gas and not making any more incursions into polar bear's territory.
[语篇解读] 本文为议论文。作者在文中阐述了保护北极熊的重要性。
1．Which is NOT the threat to the survival of polar bears according to the passage?
A．Habitat loss. B．Global warming.
C．Human's killing. D．Lack of food.
解析：细节理解题。根据第一段第二、三句“They are dying becau they are losing a gre
at deal of habitat due to human incursion(侵入)and global warming.They are dying becau of starvation as well.”可知，栖息地丧失、全球变暖及缺少食物威胁着北极熊的生存。C项没有提到。
答案：C
2．The underlined word “carnivores” ( in Para.2 ) refers to ________.
A．grass-eating animals B．meat-eating animals
C．polar bears D．Arctic als
解析：词义猜测题。由画线词后面一句“The failure to save polar bears might result in loss of the predators.”可知carnivores指“食肉动物”。
答案：B
3．If bears can't adapt to changing climates，we will probably have lost ________ by the middle of the 21st century.
A．most of polar bears B．few of polar bears
