| The gravitational pull of the Earth and
moon is important to us as we attempt to conquer more and more of outer-space.
Here’s why. As a rocket leaves the Earth, the pull of the Earth on it becomes less and less as the rocket roars out into space. If you imagine a line between the Earth the pull of the Earth and the moon, there is a point somewhere along that line, nearer to the moon than to the Earth, at which the gravitation pull of both the Earth and the moon on an object is just about equal. An object placed on the moon side of that point would be drawn to the moon. An object placed on the Earth side of that point would be drawn to the Earth. Therefore, a rocket need be sent only to this "point of no return" in order to get it to the moon. The moon’s gravity will pull it the rest of the way. The return trip of the rocket to Earth is, in some ways, A. to get the rocket into the space B. to calculate the rocket’s velocity of escape C. to guide the rocket after it leaves the Earth’s surface D. to identify the gravitational fields of the Earth and the moon [单选题]有限空间作业时，监护人员应在（ ）持续监护，与作业者进行有效的操作作业、报警、撤离等信息沟通。
A. 有限空间外 B.进入有限空间内 C.根据工作需要 [简答题]十二经别:
[判断题]配电线路和设备停电后，在未拉开有关隔离开关（刀闸）和做好安全措施前，不得触及线路和设备或进入遮栏（围栏），以防突然来电。
A.正确 B.错误 [单选题]我国现行《宪法》规定，地方各级人民代表大会每届任期为( )年。
A.三 B.四 C.五 D.二 [判断题]国家综合性消防救援队伍所属单位和人员在与队伍外人员交往中必须遵纪守法,坚决维护国家和队伍的形象。( )
A.正确 B.错误 [多选题] 公安机关可以在下列哪些地点宣告治安管理处罚决定书?()
A. 公安机关 B. 公安机关指定的地点 C. 被处罚人所在单位 D. 被处罚人的住处 [单项选择]对侧肾功正常时肾损伤肾切除指征是（）
A. 肾上极碎裂伤 B. 肾下极碎裂伤 C. 肾严重碎裂伤或肾血管撕裂严重 D. 肾被膜裂伤 E. 肾损伤 [单项选择]环境资源上的差异造成的边缘为（）。
A. 固有边缘 B. 诱导边缘 C. 人为边缘 D. 干扰边缘 我来回答: 提交
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