[originaltext] Space is a dangerous place because of rays from the sun and ot

游客2024-03-04  13

问题  
Space is a dangerous place because of rays from the sun and other stars. The atmosphere again acts as our protective blanket on earth. Light gets through, and this is essential for plants to make the food which we eat. Heat, too, makes our environment endurable. Various kinds of rays come through the air from outer space, but enormous quantities of radiation from the sun are screened off. As soon as men leave the atmosphere they are exposed to this radiation but their spacesuits or the walls of their spacecraft, ff they are inside, do prevent a lot of radiation damage. Radiation is the greatest known danger to explorers in space.  The trouble is that it is extremely difficult to be sure about radiation damage--a person may feel perfectly well, but the cells of his or her sex organs may be damaged, and this will not be discovered until the birth of deformed children or even grandchildren. Missions of the Apollo flights have had to cross belts of high radiation and, during the outward and return journey, the Apollo crew accumulated a large amount of rems, the unit of radiation. So far, no dangerous amounts of radiation have been reported, but the Apollo missions have been quite short. We simply do not know yet how men are going to get on when they spend weeks and months outside the protection of the atmosphere, working in a space laboratory. Drugs might help to decrease the damage done by radiation, but no really effective ones have been found so far.

选项 A、It is insignificant.
B、It is enormous.
C、It seems overestimated.
D、It remains unknown.

答案 D

解析 [听力原文]
What’s the result of harm radiation done to the Apollo members?
由选项推测本题考查关于it的信息。文中关键句为“no dangerous amounts of radiation have been reported”,意思是危险射线还是未知的,故正确答案为D)。
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