All but one _____ here just now. [ ]
A. is
B. was
C. has been
D. were
答案：D
以下（）其印墨透过性较佳
A.绢网
B.尼龙
C.特多龙
D.UV网
确诊二尖瓣狭窄的最可靠的辅助检查是
A．心电图B．X线摄片C．超声心动图D．心音图E．CT
