单项选择题
A.if B.when C.because D.though
A. they fear to be sued by the patients B. they care much about Their reputation C. they compete for getting more patents D. they wish to join the private medical system
A. when in one's life ambition is most needed B. what to do to reform the education system C. why parents of underachievers are ambitious D. how to help school children develop their ambition