2007职称英语（理工类）模拟试题(2)

　　7.第6部分：完形填空

Radiation

　　Space is a （51） ______ place, not only because of meteors but also because of rays from the sun and other stars. The atmosphere again （52） ______ our protective blanket on earth. Light gets through, and this is （53） ______ for plants to make the food which we eat. Heat, too, makes our environment endurable. （54） ______ 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 （55） ______ to this radiation but their spacesuits or the walls of their spacecraft, if they are inside, do prevent a lot of radiation damage.

　　Radiation is the greatest known danger to explorers in space. The unit of radiation is called "rem". Scientists have （56） ______ to think that a man can （57） ______ far more radiation than 0.1 rem （58） ______ being damaged; the figure of 60 reins has been agreed on. The trouble is that it is extremely difficult to be sure about radiation damage－a person may feel perfectly （59） ______, but the cells of his or her sex organs may be （60） ______, and this will not be discovered （61） ______ 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 journeys, the Apollo crew accumulated a large amount of rems. （62） ______, no dangerous amounts of radiation have been reported, but the Apollo missions have been quite （63） ______. 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 （64） ______ the damage done by radiation, but no really （65） ______ ones have been found so far.

　　Notes：

　　①meteor n. 流星

　　②deformed a. 畸形的

　　51. A. interesting B. dangerous C. safe D. mysterious

　　52. A. acts as B. is used C. become D. grow

　　53. A. essential B. pleasant C. critical D. dependent

　　54. A. All B. Various C. Many D. Much

　　55. A. harmed B. protected C. exposed D. covered

　　56. A. reason B. already C. explanation D. excuse

　　57. A. deal with B. put up with C. cope with D. absorb

　　58. A. with B. before C. when D. without

　　59. A. bad B. sick C. well D. safe

　　60. A. burnt B. damaged C. hurt D. destroyed

　　61. A. until B. before C. after D. while

　　62. A. So far B. Now C. However D. But

　　63. A. long B. difficult C. short D. challenging

　　64. A. increase B. fall C. solve D. decrease

　　65. A. effective B. efficient C. reliable D. trustful