使用大锤时，为防止（），必须（）。
参考答案：把手磨破；戴手套
--- I did not see your elder brother at the lecture yesterday.
---You ______him, since he went to see Chinese Zodiac---Jackie Chan’s 100th movie.
A．mustn’t have seen
B．couldn’t have seen
C．shouldn’t have seen
D．needn’t have seen
蛛网膜下腔出血的确诊方法为（）
A.脑血管造影
B.MRA
C.MRV
D.CT
E.MRI
