| Birds are literally half-asleep-with
one brain hemisphere alert and the other sleeping, according to a new study of
sleeping ducks. Earlier studies have documented half-brain sleep in a wide range of birds. The brain hemispheres take turns sinking into the sleep stage characterized by slow brain waves. The eye controlled by the sleeping hemisphere keeps shut, while the wakeful hemisphere’s eye stays open and alert. Birds also can sleep with both hemispheres resting at once. Decades of studies of bird flocks led researchers to predict extra alertness in the more vulnerable, end-of-the-row sleepers. Sure enough, the end birds tended to watch carefully on the side away from their companions. Ducks in the inner spots showed no preference for gaze direction. Also, birds dozing (打盹) at the end of the line resorted to single-h A. alert themselves to the approaching enemy B. emerge from water now and then to breathe C. be sensitive to the ever-changing environment D. avoid being swept away by rapid currents [判断题]如果外部单位用户的基建系统外网登陆密码忘记了，可以在统一权限平台，身份管理-用户维护下，选中用户后点击“重置口令”进行操作。
A.正确 B.错误 [判断题]作业票签发人或作业负责人在作业前应组织开展作业风险动态评估，确定作业风险等级。
A.正确 B.错误 [多选题]属于上层建筑的社会意识形式称为社会意识形态,主要包括(2分)( )
A. 政治法律思想 B. 哲学 C. 道德 D. 自然科学 [单项选择]Questions 21～24 are based on the following news from the BBC or the VOA. At the end of the news item, you will be given 20 seconds to answer the two questions.
Now listen to the news. According to the passage, before the agreement was announced Monday, the two sides had been bargaining for ______days. A. 4 B. 5 C. 6 D. 7 [单选题]该培训参加的人员应满足的条件是()。
A. 年满18周岁 B. 男性 C. 学历高中以上 [单选题]高处作业时,严禁( ),不得违规操作。
A.睡觉 B.讲话 C.停留 [单选题]坚持可持续发展,必须加强建设生态文明,必须放在突出地位的是( )。
A..生态文明建设 B..经济建设 C..保护环境 D..尊重自然 [单选题]机上发现传染病病人或疑似病人时,下列的处理程序中错误的是:( )
A.临时划分病人区域和健康人群区域 B.对旅客进行安抚,稳定旅客情绪 C.迅速丢弃传染病人或疑似病人的物品 我来回答: 提交
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