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【单选题】
盒子里装有大小质地都相同的两个红球和两个黄球，搅匀后从中摸出一个球，然后放回搅匀，再摸出第二个球，则取出的恰是两个黄球的机会是
[ ]
A.
B.
C.
D.
无法预测
参考答案：
参考解析：
刷刷题刷刷变学霸
举一反三
【单选题】第二篇 Sleep We all know that the normal human daily cycle of activity is of some 7 - 8 hours’ sleep alternating with some 16 - 17 hours’ wakefulness and that, broadly speaking, the sleep n...
A.
people hate the inconvenience of working on night shifts.
B.
your life is disturbed by changing from day to night routines and back.
C.
not all industries work at the same hours.
D.
it is difficult to find a corps of good night workers.