问题 单项选择题

室温下碳在奥氏体中的溶解度很小约为()。

A.0.015%~0.025%

B.0.02%~0.03%

C.0.025%~0.035%

D.0.027%~0.037%

答案

参考答案:B

完形填空

阅读短文,根据短文内容回答问题。(共10分,每小题2分)

Have you had this experience? You are watching a movie. A man is shooting(射击) on the screen. The picture is so real that you think he is shooting at you.

Three-dimensional(3D)movies use special technology to make pictures seem more real and exciting than two-dimensional ones.

So far we can only see 3D movies in the cinema with a special screen and projector(放映机). But soon, we will be able to watch them in our living rooms. Last month, Woods Company told reporters that it plans to bring 3D televisions to homes in the near future.

“The 3D train is on the track, and we are ready to drive it home,” said the President. 3D movies and TV programs are fun to watch, but do you know how they are made? It is much easier to understand if we do an experiment.

Hold one of your fingers up at arm’s length and close one eye. Then try closing the other eye. As you move between open eyes, you should see your finger “jumping” left and right against the background.

This happens because our two eyes are about 4 cm away from each other. The separation causes each eye to see the world from a different angle(角度). The brain puts these two views together. What you see becomes three-dimensional.

3D movies are made using two video cameras at the same time, which creates two different images(影像). When the movie plays in a cinema, two projectors put the two images on the screen. With a pair of 3D glasses, the two images are separated and each image only enters one eye. Your brain puts the two pictures back together, and the pictures on the screen become three-dimensional.

小题1: Do 3D movies use special technology to make pictures?

小题2:What does Woods Company plan to do in the near future?

小题3: What can you see when you move your finger between open eyes?

小题4: How many video cameras are needed when making a 3D movie?

小题5: What is the passage mainly about?

阅读理解

阅读理解。

     The scene in the Hollywood movie The Day After Tomorrow, where global warming could soon turn the

global climate (气候) into a new ice age, may never occur, according to new research.

     The next ice age could be 15,000 years away, say European scientists who last month announced a

continuous record of 740,000 years of climate date (数据) obtained from the Antarctic ice.

     Scientists from 10 nations have now almost completely drilled through a 3,000-meter depth of ice high in

the Antarctic mainland. They figure out that the area where summer temperatures can fall to, has at least

900,000 years of snowfalls, kept as neatly as the growth rings of a tree. And the ice and air caught in each

layer (层) have begun to answer questions about the climates in the past.

     The results show that there have been eight ice ages in the past 740,000 years and eight warmer periods.

And by comparing the pattern of global conditions today with those of the past, the researchers reported in

Nature that the present warm period could last another 15,000 years.

     Research suggests that there is a very close connection between greenhouse gas levels and global average

temperatures. It also shows that carbon dioxide (二氧化碳) levels are the highest for at least 440,000 years.

     "If people say to you: the greenhouse effect is a good thing because we would go into an ice age

otherwise, our date say no, a new ice age is not hanging over our heads," said Eric Wolff from the British

Antarctic Survey." Now we have eight examples of how the climate goes in and out of ice ages … and you

can learn what the rules are that go into the climate models that tell us about the future."

     Scientists found that whenever temperatures rose in the frozen record, so did carbon dioxide level. " In

440,000 years we have never seen greenhouse gas get as thick as it is today," said Dr Wolff.

1. In drilling through the ice in Antarctica, scientists have found that _____.

A. the lowest temperature there is

B. the depth of ice is 3,000 meters

C. the ice has existed for 15,000 years

D. snowfalls are kept in certain patterns

2. The information of the global climate conditions in the past can be obtained through _____.

A. separating carbon dioxide from the air

B. examining the growth rings of trees

C. comparing temperatures in different areas

D. studying the ice and air caught in each layer

3. We can infer from Eric Wolff's words that _____.

A. there is something wrong with the data

B. greenhouse effect is always a bad thing

C. a new ice age will not come in the near future

D. greenhouse gas will get thick in the future

4. What would be the best title for the passage?

A. Research over the Antarctic area.

B. Warm period to last about 15,000 years.

C. Report on the eight ice ages in the past.

D. Hollywood movies and the global climate.