He doesn’t know when he should go there．（改为同义句）
He doesn’t know________ ________go there．
（2014山东滨州）根据汉语意思和提示词翻译句子
我爸爸过去经常开车上班，现在坐公交车了。（used to do sth．）
_______________________________________________________________________________
—Excuse me．what’s this for？
—It’s a cleaner and it________to pick up dirt．
A．uses
B．is used
C．is using
D．used
We believe scientists will________a way to solve the air pollution．
A．set off
B．put off
C．come up with
D．catch up with
Could you________the restaurant and order sortie take－away food for me？I’m a little hungry．
A．call up
B．call on
C．call at
D．call for
—Attention，please．The plane has to be________because of the heavy rain．
—Oh，bad luck！We have to wait now．
A．put on
B．put off
C．put up
D．put away
