| It is hard to track the blue whale, the
ocean’s largest creature, which has almost been killed off by commercial whaling
and is now listed as an endangered species. Attaching radio devices to it is
difficult, and visual sightings are too unreliable to give real insight into its
behavior. So biologists were delighted early this year when with the help of the Navy they were able to track a particular blue whale for 33 days monitoring its sounds. This was possible because of the Navy’s formerly top-secret system of underwater listening devices spanning the oceans. Tracking whales is but one example of an exciting new world just opening to civilian scientists after the cold war as the Navy starts to share and partly uncover its global network of underwater listening system built over the decades to track the ships of potential ene A. an effort to protect an endangered marine species B. the civilian use of a military detection system C. the exposure of a U.S. Navy top-secret weapon D. a new way to look into the behavior of blue whales [判断题]1946年1月,新政治协商会议召开,通过了有利于人民的五项协议。
A.正确 B.错误 [多选题]有砟轨道主要采用弹条有()类型扣件
A.Ⅴ B.Ⅳ C.Ⅱ D.FC [单项选择]在农业生产中，只要不超过合适的限度，肥料施得多，农作物的产量就上升；肥料施得少，农作物的产量就下降，由此可知，施肥量与农作物的产量有着密切的关系。
以下哪项使用的逻辑方法与题干最为类似( ) A. 敲锣有声，吹箫有声，说话有声。这些发声现象都伴有物体上空气的振动，因而可以断定物体上空气的振动是发声的原因 B. 用锯锯物，锯会发热；用锉锉物，锉也会发热；在石头上磨刀，刀会发热；用枪射击时，枪膛也会发热。可见，摩擦生热 C. 在有空气的玻璃罩内通电击铃，随着抽出空气的量的变化，铃声越来越小，若把空气全部抽出，则完全听不到铃声。可见，空气多少是发出声音大小的原因，空气有无是能否听到铃声的原因 D. 棉花是植物纤维，疏松多孔，能保温；积雪是由水冻结而成的，有40%至50%的空隙，也是疏松多孔的，能保温，可见，疏松多孔是能保温的原因 [单项选择]自动喷水灭火系统配水管道的工作压力不应大于（）Mpa。
A. 0.80 B. 1.40 C. 1.20 D. 1.50 [判断题]铜和铝搭接时，在干燥的室内铜导体应搪锡，在室外或特殊潮湿的室内应使用铜铝过渡片。
A.正确 B.错误 [多项选择]硬齿面齿轮减速机的特点是（）
A. 运行平稳 B. 噪音低 C. 效率高 D. 使用寿命长 [单选题] 固体可燃物燃烧而引起的火灾是()。(易)
A.A类火灾 B.B类火灾 C.C类火灾 D.D类火灾 我来回答: 提交
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