When I ________ home, I caught a thief stealing from a passerby.
A．headed B．was heading
C．has headed D．had headed
Up to now, thousands of red phone boxes, the old image of Britain, ________ due to mobile phones.
A．removed B．have removed
C．were removed D．have been removed
This is a promising company as its employees ________ to think outside the box and develop creative solutions.
A．encourage B．have encouraged
C．were encouraged D．are encouraged
I can't understand why he ________ so selfish. He isn't usually like that.
A．was B．had been
C．is D．is being
—How long have you been going to work on foot?
—Since last month when I ________ from a heart attack.
A．recovered B．have recovered
C．was recovering D．would recover
Allen has decided that he will be an engineer by the time he ________ twenty.
A．had beenB．is going to be
C．will beD．is
