题目内容
Of the 2000 stock investors ________ last month, 90% was found ________ in financial knowledge.
A. surveyed; lacking B. having been surveyed; to lack
C. surveyed; lacked D. to have been surveyed; lack
For more than twenty years scientists have been searching for signs of life on other planets. Most of these searches have been done over the radio. The hope is that someone in outer space may be trying to get in touch with us. Scientists also have sent radio and television messages on spaceships traveling through space, on the chance that someone may be receptive (善于接受的) to such messages.
Scientists are using powerful radio telescope to listen to signals from about 1,000 stars, all within 100 light years of earth. In addition, they will scan (扫视) the entire sky to “listen” for radio messages from more distant stars. Using a computer, they will be able to monitor more than eight channels at one time. Scientists are looking for any signal that stands out from the background noise.
Of the 200 billion stars in the Milky Way galaxy (银河星系), scientists find that five percent are like our sun. Perhaps half of them have a planet like earth. Such a planet would be a reasonable distance from the star for temperatures to be right for the evolution of life. Based on the inhabitable (that can be lived in) planets in our galaxy, most scientists agree that chances are likely that one or more of these planets support some life.
However, many scientists wonder whether intelligent (有智力的) life exists on other planets. Some believe that twenty years of searching without any intelligible (可理解的) messages shows that no one is out there. They say that the evolution of intelligence comparable to ours is unlikely.
Other scientists believe that our search hasn’t been long enough to rule out the possibility that intelligent life exists in our galaxy. Although our sun family in only about five billion years old, our galaxy is about 20 billions years old. In that time, some scientists think it is likely that civilizations are much more advanced than ours. Perhaps these civilizations (文明) send us no signals; perhaps we have not recognized the signals they have sent us. If we hope to find intelligent life, these scientists believe that we have to keep looking.
【小题1】According to the passage, how many planets in our galaxy might be inhabitable?
A.5 billion | B.10 billion | C.15 billion | D.200 billion |
A.how scientists are looking for signs of life on other planets |
B.why scientists are looking for signs of life on other planets |
C.where scientists are looking for signs of life on other planets |
D.when scientists are looking for signs of life on other planets |
A.find | B.follow | C.check | D.form |
A.The earth is one of the oldest planets in our galaxy. |
B.Most scientists believe that there is intelligent life on other planet. |
C.Scientists are trying different ways to find signs of life on other planet. |
D.Scientists don’t believe that there might be life on other planets. |
AVERAGE RESOURCES | |
620 m3 water | If we put fresh water and sea water together, we can each have 620 m3 water. But remember, sea water is too salty for us to drink if the factories don’t process it first. So, 620 m3 is little. Saving water in daily use is important. |
0.5 hectares of forests | There are 3.869 billion hectares(公顷) of forests on Earth. But we are losing them mainly because we cut trees too much. If we calculate(计算)at the size of a football field, we are losing 343,000 football fields every day, or 1,431 per hour, or 24 per minute! |
1.5 centimeters long corals(珊瑚) | All the corals that we have now spread for about 100,000 km in 109 countries. But each of us can only have such a little piece, because seas are getting polluted and corals are dying. |
33 stars | According to the latest report, there are 200 billion stars in the Milky Way. Each of us can have 33 of them. Unfortunately, we cannot see most of the 200 billion stars from Earth. We can only see about 6,000 stars. If we don’t use telescopes or we have bad weathers, we can only see about 2,000 stars. |
90kg rice | On average, we harvest 0.54 billion tons of rice each year round the world and each of us can have 90 kg. Asia produces and eats 90% of all the rice. How long will it take you to eat up this 90 kg rice? |
1 iceberg | Luckily, we still have icebergs to share when Earth gets warmer and warmer. Each of us can have an iceberg of 170m×170m×170m. Up to 10% of Earth surface is covered by ice. There is 31,000,000km3 of ice on Earth in all. |
A.over 620m3 | B.more than 620m3 | C.far less than 620m3 | D.only 620m3 |
A.the man-made damage | B.the climate change |
C.the construction of many football fields | D.the environmental pollution |
A.all the stars | B.about 2,000 | C.about 200 billion | D.about 6,000 |
A.less water | B.fewer icebergs | C.fewer corals | D.less rice |