浇注时，铁水温度太低，铁水量不足，浇注后铸件将出现何种缺陷（）
A.缩孔
B.气孔
C.浇不足
参考答案：C
关于CF型心电图机的描述，不正确的是（）。
A.泄漏电流小于10μA
B.应用部分浮地隔离
C.对电击有高度防护
D.不能直接用于心脏
E.具有隔离措施
-I left my handbag on the train, but luckily someone gave it to a railway official.
-How unbelievable to get it back! I mean, someone________ it.[ ]
A．will have stolen
B．might have stolen
C．should have stolen
D．must have stolen
