避孕套密封包装感观缺陷包括（）。
A.铝膜分层
B.漏油
C.掉色
D.空袋
参考答案：A, B, C, D
To their great fear，they found________in the heaviest snowfall they had ever had.[ ]
A．they were catching
B．themselves caught
C．they had caught
D．themselves catching
为明确诊断，最有鉴别价值的辅助检查为
A．脑血管造影
B．头部CT
C．腰穿
D．TCD
E．SPECT
