题目内容
What the doctors really doubt is _____ my mother will recover from the serious disease soon.
A. when B. if C. whether D. why
C
在引导主语从句、表语从句和同位语从句时,只能用whether,而不能用if。句意为: 医生真正怀疑的是我母亲能否很快从重病中恢复过来。
Rising levels of carbon dioxide in the atmosphere are a major cause of climate change, and now a new study has confirmed that atmospheric CO2 is also affecting the ocean chemistry and potentially harming sea life.
Montana State University scientist Robert Dore has been researching the water in the Pacific Ocean for almost two decades. We've been going to the same spot in the Pacific Ocean, and we try and characterize long-term change in the open ocean environment. And one of the key things that we measure is CO2 levels. And we've been able to record this increasing quantity of atmospheric CO2 into the ocean.
Scientists expected that as atmospheric CO2 increased, more and more of the carbon dioxide would be absorbed into the ocean, affecting the chemical balance of the sea water, with a potentially harmful impact on shellfish and coral in particular.
"As carbon dioxide dissolves(溶解) in the water, or seawater in this case, it forms a weak acid, carbonic acid," Dore explains. "And therefore, as the concentration of CO2 in the atmosphere goes up and that exchanges with the surface seawater, it drives the PH down, and makes it more acidic."
The seawater Dore and his colleagues have analyzed confirms what the theory predicts.
The effect was particular striking at about 250 meters down, and again at 500 meters. Dore and his colleagues came up with two possible explanations. It could be that surface water picked up CO2 and then moved to those depths. Or there could be a biological explanation.
"It's important to realize that the oceans are really becoming acidic. And it can have negative(消极的) impacts on a whole variety of sea life from fish to coral. It's potentially catastrophic."
【小题1】What can be the best title of the passage?
A.Sea Life Facing Danger |
B.Scientist Researching Seawater |
C.Oceans Becoming More Acidic |
D.Climate Change Affecting Seawater |
A.more corals will appear in the sea |
B.the surface water is becoming warmer |
C.the chemical balance of the seawater is affected |
D.the PH of the ocean out here has been increasing |
a.Sea life is endangered.
b.CO2 goes into the surface water.
c.The ocean chemistry is affected.
d.CO2decreases the PH and makes the seawater more acidic.
e.CO2 levels in the atmosphere go up.
【小题4】Scientist Robert Dore came to the conclusion based on .
A.his research and analysis |
B.the expectation of other scientists |
C.some former theory |
D.a major cause of climate change |
The blue tits(山雀) have been inspecting the nest-box again this year. The male is the house-hunter but the female will make the final choice. He lands at the hole and turns his head to expose his white cheeks as a signal to attract the female from where she has been feeding.
Among many birds that nest in holes, the male has a light-coloured patch on its plumage(鸟羽) which acts as signal for drawing the female’s attention to a suitable nesting-place. Unlike the blue tit, the redstart(红尾鸲) may be only the male that strikingly coloured and the female is not beautiful.
A few years ago I was lucky enough to spot a pair of redstarts in action in a Walsh wood. The male was leading an interested female to holes that he had previously(先前) checked out. He sat at the entrance of each hole and put his head on to show off his white forehead, or his head in to reveal(显露) his tail.
If the female failed to react to his visual signals, the male sometimes sang for extra effect, while gliding towards her on spread wings and tail. Once the female accepts by following the male through the hole the displays stop, you must be at the right place at the right time to watch them.
【小题1】How do the blue tits choose their nest?
A.They choose their nest together. | B.The male chooses their nest. |
C.The house-hunter chooses their nest. | D.The female chooses their nest. |
A.how the male made his tricks |
B.how an interested female played with the male happily |
C.what the male displayed and won the female |
D.that the male tried his best but failed to attract the female |
A.at any time | B.regularly | C.in April | D.occasionally |
A.a bird expert | B.a bird-hunter | C.a bird raiser | D.a scientist |
There is no doubt about it. The best way to learn new words is to do it unconsciously. I don’t mean while you’re unconscious. I mean while you are unconscious of the fact that it is sinking in.
That is how I learnt the 30,000 words in my vocabulary by living in an English-speaking world, mother tongue. I just pick them up. But some of them may be misunderstood. Now, to misunderstand does not mean not to understand. To misunderstand is to understand but incorrectly.
The 5% mislearnt of all the words we “know” will be the least frequently used words, as the more frequently used words are less likely to be mislearnt. Some of the misunderstanding may live with all our lives, without knowing that we got them wrong.
Many English teachers think that this natural method of learning words in one’s own mother tongue can be used for a second language learning. They teach their students how to play the Guessing Game. “There is no time to look up in your dictionaries all the new words you come across,” they will say. “You have to practice guessing what the word means from the context.”
This method of guessing in a second language learning does not work. It may succeed in many cases, but results in hundreds or thousands of wrongly-guessed meanings of words.
And what’s more, there are more separate meanings than there are words themselves. Our learners’ dictionaries usually have many meanings. A good dictionary is what makes self-learning possible.
Don’t guess! Look it up!
【小题1】 It is certain that the best way to learn new words is ______.
A.to learn them by oneself |
B.to learn by living in an English-speaking world and using them frequently |
C.to guess them from the context |
D.to get more separate meanings of each word |
A.the 30, 000 words |
B.English teachers |
C.misunderstood words |
D.frequently used words |
A.Some of the words the writer knows must have been misunderstood. |
B.Most of the 30, 000 words the writer learned are frequently used ones. |
C.How many words the writer got wrong are not known. |
D.All the words the writer knows were learned by reading them. |
A.when somebody is conscious, he or she usually can’t learn new words by heart |
B.we must use the words as often as possible in order to master them |
C.it’s the best way to learn new words that one should only guess their meanings from the context |
D.only dictionaries can help us learn language well. |