Question

Some children were seen ( )here in the garden all the morning .It must have been ( )who picked flow

要解析哦...。着重一下后面的空。
Some children were seen ( )here in the garden all the morning .It must have been ( )who picked flowers.
A.playing;they.B.to play Cplaying;them Dplay;them(我记了个答案选A啊...）

Answer 1

选C。
首先，第一空应是动作正在进行的时候被看见，即“有人看见孩子们在花园里玩”中，玩的动作是正在进行的，故使用一般进行式；其次，第二个空的词在句中作宾语，故应使用宾格代词THEM，而WHO引导的从句是对THEM的补充说明。

Answer 2

playing,them
see sb. doing sth.的被动形式是sb. be seen doing sth.
them是他们的意思，是说孩子们摘了花，原句最后的单词应为flowers.

Answer 3

playing,them

Answer 4

b