Whatthe rescue workers are doing will also calm the person,______him know that help is on the way.A.to letB.lettingC.letsD.to have let答案是B为什么不选C呢？B是伴随状语吗?谢谢

1。The storm left,______a lot of damagetothis area.A.causedB.tohave causedC.tocauseD.havingcaused2.______in the mountain for a week,thetwostudents were finally saved by thelocal police.A.Having lostB.LostC.Being lostD.Losing第一题选D,第二题选B，能不能 ...

Whatthe rescue workers are doing will also calm the person,______him know that help is on the way.A.to letB.lettingC.letsD.to have let答案是B为什么不选C呢？B是伴随状语吗?谢谢

Ｔhe man we followed suddenly stopped and looked as if ______whether he was going in the right diretion.A.seeingB.having seenC.to have seenD.to see答案是D为什么不选A呢Idon'tknow whetheryou happen _________ ,butI'm going to study in the USA this summer ....

# 为了抽查某城市自行车年检情况,在该城市主干道上采取抽取车牌个位数为6的自行车检查,这种抽样方法是?答案是系统抽样.可是系统抽样是不放回抽样啊,这个明显是放回抽样嘛!!!为什么呢??