When ____ to compare the education system of China and Britain, the professor gave no answer．
A．ask B．asking C．asked D．to ask
Why not get some work experience first ______ go straight on to university?
A．other than B．rather than C．more than D．less than
What if we meet with a situation _______ none of us are able to deal with?
A．where B．in which C．what D．that
His lack of professional knowledge _______for the failure of the experiment.
A．accounted B．explained C．counted D．contributed
Tom was about to close the window his attention was caught by a bird.
A．when B．if C．and D．till
—Do you have any idea why Mark is leaving?
—No. In fact，everyone is _________about it.
A．doubtful B．curious C．enthusiastic D．annoyed
