一个袋中装有两个红球,一个白球,第一次摸出一个球,放回拌匀,再任意摸出一个,则两次都摸到白球的概率是( )
----Did you forget about my birthday?
---- I’ve booked a table at Michel’s restaurant for this evening.
A.What then?
B.I’m afraid so.
C.how could I?
D.For sure.
设备自然寿命