诊断风湿性心脏病二尖瓣严重损害,最重要的X线征象是()。
A.肺循环高压
B.左心房重度增大
C.二尖瓣区钙化
D.右心房重度增大
E.重度间质性肺水肿
参考答案:C
与甲醛一硫酸反应的用于鉴别的是()
A.阿司匹林
B.庆大霉素
C.苯巴比妥
D.硫喷妥钠
E.司可巴比妥
How many students ________ there in your class last term?[ ]
A. is
B. are
C. was
D. were