Space is a dangerous place, not only because of meteors (流星) but also because of

游客2024-02-17 76

问题 Space is a dangerous place, not only because of meteors (流星) but also because of rays from the sun and other stars. The atmosphere again acts 【C1】______ our protective blanket on 【C2】______ . Light gets through, and this is essential 【C3】______ plants to make the food which we 【C4】______ . Heat, 【C5】______ , makes our environments tolerable and some ultraviolet rays (紫外线) penetrate the 【C6】______ . Cosmic (宇宙的) rays of various kinds come 【C7】______ the air from outer space, but 【C8】______ quantities of radiation from the sun are screened off. As 【C9】______ as men leave the atmosphere they are 【C10】______ to this radiation; 【C11】______ their spacesuits or the walls of their spacecraft, if they are inside, 【C12】______ prevent a lot of radiation damage.
Radiation is the greatest known danger to explorers in 【C13】______ . Doses of radiation are measured in 【C14】______ called "rems (雷姆)". We all 【C15】______ radiation here on earth from the sun, from cosmic rays and from radioactive minerals. The" 【C16】______ "dose of radiation that we receive each year is about 100 millirems; it 【C17】______ according to where you live, and this is a very rough estimate. Scientists have reason to think 【C18】______ a man can 【C19】______ up with far more radiation
【C20】______ this without being damaged; the figure of (60) rems has been agreed. [br] 【C5】

选项 A、again
B、also
C、besides
D、too

答案 D

解析逻辑衔接题，空格所在句讲的是heat (热)对地球的作用，与前一句在意义上是并列关系，因此应选表并列关系的词，选项中again意为“再次”，应排除；also在句中通常不用逗号隔开，应排除；besides 意为“除.v之外”一般用在句首，应排除；too 可用在句中，且可用逗号隔开，所以D正确

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