____behind the door,she wanted to give him a surprise.A hiding B hidden C to hide应该选哪一个?为什么?但是答案给的是B，怎么回事？

在横线上填有oo的单词(Please give this ball back _______?/You can find a ____behind the door. ____behind the door,she wanted to give him a surprise.A hiding B hidden C to hide应该选哪一个?为什么?但是答案给的是B，怎么回事？ Look,the children are hiding ____behind the tree.let's go and find them. Look,the children are hiding ____behind the tree.let's go and find them.请问横线上填什么? feel the door是什么意思 next to the door next to the door Open the door,please. clear the door S(),the door opened stand in the door open the door please,-------- ---------? keep the door ( ) ,pIease Leave the door open. leave the door对吗? Get the Door 歌词 dead outside the door near the door.