锻造过热是由于加热温度过高而引起的（）现象，碳钢以出现（）为特征，工模具钢以（）为特征。
参考答案：晶粒粗大，魏氏组织，一次碳化物角状化
The audience were ________ by his ________ performance on the stage.
A．amazed; amazed
B．amazed; amazing
C．amazing; amazed
D．amazing; amazing
做尿妊娠试验时，容易获得阳性结果的尿液是
A．晨尿B．12h尿C．24h尿D．10am尿E．与时间无关
