|
Radiation Effect 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 as our protective blanket on earth light, gets through, and this is essential for plants to make the food that 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 spacecrafts, 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" (“雷姆”) A. is insignificant B. seems overestimated C. is enormous D. remains unknown [判断题]矿井通风是防止瓦斯积聚的基本措施，只有做到有效地控制供风的风流方向、风量和风速，漏风
少、风流稳定性高，才能保证 随时冲淡和排除瓦斯。( ) A.正确 B.错误 [单选题] 依据《中国南方电网有限责任公司应急管理规定》第六条的规定，各级应急办由主任、副主任和成员组成；应急办主任可由（ ）担任。
A. 安全总监（总师）或安监部门主要负责人 B. 安监部副经理 C. 市场部经理 D. 人资部主任 [填空题]According to recent surveys， 72% of all Americans believe that the United States
government is （46） hi____ information about UFOs. Almost 68% of people think that the government has secret knowledge of extraterrestrial life. It is not （47） ____ （surprise） that the government has come under more and more（48）pr____ to declassify its UFO records and make them public. A variety of different groups have been involved in these efforts.
One group to become involved is called CFI， the Coalition for Freedom of Information， John Podesta， who was White House Chief of Staff during Bill Clinton’s （49） ____ （president）， is one of the many high-powered people active in this group. CFI’s aim is not to prove the（50）____（exist）of extraterrestrial life，but to make it easier for scientists in general to study unexplained aerial phenomena. Podesta and his group has asked the Pentagon to declassify its UFO records and therefore provide scientists （51） ____ data that will help in the study of UFOs.
CFI ha
[单选题]下面（ ）是轿厢所属构件。
A.曳引钢丝绳 B.电缆支架 C.层门地坎 D.导靴 [单项选择]可用于膜控片的致孔剂（）
A. 单棕榈酸甘油酯 B. 聚乙二醇6000 C. 甲基纤维素 D. 甘油 E. 乙基纤维素 我来回答: 提交
|
