题目

一人造地球卫星绕地球做匀速圆周运动，假如该卫星变轨后仍做匀速圆周运动，但速度变小，则变轨后卫星  A．处于平衡状态   B．重力势能增大   C．万有引力变大   D．运行周期变小 答案：BOf all __________ reasons for my decision to become a university professor, my father’s advice was __________ most important one. A. the; a     B. 不填; a     C.  不填; the     D. the; the