奥氏体不锈钢采用（）的目的是防止晶体间腐蚀
A超低级焊丝
B高碳焊丝
C普通碳焊丝
D优质焊丝
参考答案：A
Li Gang, a police officer said that little about what his son _____ he know the moment all the media reported the traffic accident _____ in Hebei University．
A．did did; happening
B．did do; happened
C．would do; happening
D．could do; happened
蜗轮减速机青铜轮缘与铸铁轮的配合，一般采用（）。
A、H7/M6
B、H7/S6
C、H7/N6
D、H7/C6
