________(fail)severaltimes,theyneedsomeencouragement.
________they'vegottoknoweachotheralittlebetter,theygetalongjustfine.
Iwon't________thosechildrenmakinganoiseinmyhouse!
设A，B是两随机事件，则事件AB表示（）
Hefellasleepimmediatelylastnight;hemust________(be)verytired.
