摘挂钩工作必须（）操作。
A.随意
B.细心
C.马虎
参考答案：B
肾前性急性肾衰尿沉渣镜检常见管型（）
A.红细胞管型
B.白细胞管型
C.棕色管型
D.透明管型
E.颗粒管型
his play, , is very wonderful: there are many interesting characters in it.
A．out of the question
B．on the whole
C．in doubt
D．under no condition
