冷裂纹产生的三大主要因素是焊接接头的()。
A.应力
B.含氢量
C.淬硬组织
D.压力
参考答案:A, B, C
If you want to keep fit, you can't eat ______ food like this. [ ]
A. much too
B. too much
C. too many
D. many too
Java Application源程序文件的扩展名为( )。
A..java
B..class
C..html
D..exe