—Why do you look so puzzled?
—Oh，I ________ over a most difficult maths problem.
A．thought B．have thought
C．am thinking D．think
—Peter！Let's hurry.The boss is coming.
—Oh，I was afraid that we ________ her.
A．miss B．had missed
C．will miss D．have missed
The past two years ________ a sharp rise in oil price，which adds to the burden of auto transportation industry.
A．witnessed B．has witnessed
C．is witnessing D．witnesses
—Jack is always studying hard and does well in all subjects.
—No wonder he ________ to be admitted to Beijing University.
A．is expecting B．will be expected
C．is expected D．will expect
Just an hour ago he was telling me on the phone that he ________ home right after the work.
A．comes B．came
C．would come D．will come
Tom is very happy in China during this period because his Chinese ________ every day.
A．has improved B．is improving
C．improved D．is improved
