___________ your car unlocked outside means ___________ trouble.
A．Leaving; to invite B．Leaving; inviting
C．To leave; to invite D．To leave; being inviting
_________ to reach them on the phone, we sent an email instead.
A．Fail B．Failed C．To fail D．Having failed
What shall human beings do if oil sometime in the future?
A．will run out B．runs out of C．runs out D．will be run out
Chen Chunlong is a hero of Liaocheng can be proud.
A．who B．whom C．that D．which
It was not until mid-night_______ they reached the camp site.
A．that B．when C．while D．before
－Why not have a meeting to discuss about it?
－ .
A．It’s hard to answer B．I don’t know, either
C．Because we have no time left D．That sounds fine to me
