概括大意(第1~8题,每题1分,共8分)
下面的短文后列出了8个句子,请根据短文的内容对每个句子做出判断:如果该句提供的是正确信息,请选择A;如果该句提供的是错误信息,请选择B;如果该句的信息文中没有提及,请选择C.
Icy Microbes
1. In ice that has sealed a salty Antarctic lake for more than 2,800 years,scientists have found frozen bacteria and algae that returned to life after thawing. The research may help in the search for life on Mars,which is thought to have subsurface lakes of ice.
2. A research team led by Peter Doran of the University of Illinois at Chicago drilled through more than 39 feet of ice to collect samples of bacteria and algae. When Doran’s team brought them back and warmed them up a bit,they sprang back to life.
3. Doran said the microbes have been age-dated at 2,800 years old,but even older microbes may live deeper in the ice sheet sealing the lake,and in the briny water below the ice. That deeper ice and the water itself will be cautiously sampled in a later expedition that will test techniques that may one day be used on Mars.
4. Called Lake Vida,the 4.5-square—kilometer body is one of a series of lakes located in the McMurdo Dry Valleys of Antarctica,some 2,200 kilometers due south of New Zealand. This lake has been known since the 1950s,but people ignored it because they thought it was just a big block of ice. While at the site for other research in the 1990s,Doran and his colleagues sent radar signals into the clear ice covering the lake and were surprised to find that 62 feet below there was a pool of liquid water that was about seven times more salty than seawater.
5. That prompted the researchers to return in 1996 with equipment to drill a hole down to within a few feet of the water layer. At the bottom of this hole,researchers harvested specimens of algae and bacteria.
6. The researchers will return in 2004 equipped with instruments that are sterilized. They will then drill through the full 62 feet of ice and sample some of the briny water from the lake for analysis. The water specimen will be cultured to see if it contains life. Specimens from the water are expected to be even older than the life forms extracted from the ice covering.
练习:
1.Paragraph 2 _____
2.Paragraph 3 _____
3.Paragraph 4 _____
4.Paragraph 6 _____
A. Significance of Testing Techniques for Sampling Microbes in the Deep Ice Sheet
B. Special Features of Lake Vida
C. Later Expedition on Mars
D. 2004 Revisit Planned for Collecting Lake Water Specimens
E. Antarctic Frozen Life Sampled and Revived
F. Accidental Discovery of Ice-sealed Lake Water in Antarctica
5.Scientists ignored Lake Vida because they thought that a lake of ice _____.
6.Scientists expect that the life,if found in deeper water below the ice sheet,_____.
7.What the scientists will do in 2004 _____.
8.The salt concentration in the liquid water of Lake Vida _____.
A. is found to be a great deal higher than that of seawater
B. was of little scientific value
C. may be older than that collected below 39 feet of ice
D. might have come from Mars
E. is to collect some briny lake water for analysis
F. may return to life sooner than microbes frozen in the surface ice