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问题 选择题

质量为2kg的小车以2m/s的速度沿光滑的水平面向右运动，若将质量为2kg的砂袋以3m/s的速度迎面扔上小车，则砂袋与小车一起运动的速度的大小和方向是：（      ）

A．2.6m/s，向右

B．2.6m/s，向左

C．0.8m/s，向右

D．0.5m/s，向左

答案

答案：D

选择题

旅游业被称为“朝阳产业”，是因为（  ）

A．旅游业在国民经济中的地位和作用越来越重要

B．旅游业可以提供大量就业机会

C．旅游业促进国民素质和生活质量的提高

D．旅游业对环境保护具有促进作用
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单项选择题

Why is (111) fun What delights may its practitiopect as his reward First is the sheer joy of making things. As the child delights in his mud pie, so the adult enjoys building things, especially things of his own design. Second is the pleasure of making things that are useful to other people. Third is the fascination of fashioning complex puzzle-like objects of interlocking moving parts and watching them work in subtle cycles, playing out the consequences of principles built in from the beginning. Fourth is the joy of always learning, which springs from the (112) nature of the task. In one way or another the problem is ever new, and its solver learns something: sometimes (113) , sometimes theoretical, and sometimes both. Finally, there is the delight of working in such a tractable medium. The (114) , like the poet, works only slightly removed from pure thought-stuff. Few media of creation are so flexible, so easy to polish and rework, so readily capable of realizing grand conceptual structures.
Yet the program (115) , unlike the poet’s words, is real in the sense that it moves and works, producing visible outputs separate from the construct itself. It prints results, draws pictures, produces sounds, moves arms. Programming then is fun because it gratifies creative longings built deep within us and delights sensibilities we have in common with all men.

A．poet

B．architect

C．doctor

D．programmer
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