用括号内所给动词的适当形式填空。
小题1:We ________(watch) the boys ________(play) basketball on the playground when something strange happened.
小题2:I don’t know what _________ (happen)to him just now.
小题3:Computers are useful to us. But some students only use them ________ (play) games.
小题4:–--Would you mind ________(take) photos with me?
--- Of course not. When I miss you, I can have a look.
小题5:You may go to play football as soon as your homework ________(finish).
小题6:Middle school students ________(tell) not to smoke.
小题1:were watching, playing
小题2:happened
小题3:to play
小题4:taking
小题5:is finished
小题6:are told
小题1:本题的含义为当某事发生的时候我们正在操场上看男孩们打篮球，表示过去正在做某事用过去进行时，本题主句为复数，故结构为were watching，看某人正在做某事可以写成watch sb doing，故本题空格处填were watching, playing。
小题2:表示过去发生的事用过去时，故本题空格处填发生的过去式happened。
小题3:使用某物做某事可以写成use sth to do，故本题空格处填to play。
小题4:mind后通常跟动名词doing作为宾语，故本题空格处填taking。
小题5:本题as soon as后跟的从句主语为动作的承受者，故从句使用被动的结构be+过去分词，故本题空格处填is finished。
小题6:本题的主语为动作的承受者，故本题使用被动结构be+动词tell的过去分词，故本题空格处填are told。