选择100%射线探伤检查时,对球壳厚度大于38mm的焊缝还应做超声波探伤复检,复检长度不应小于所探焊缝总长的( )。
A.10%
B.20%
C.30%
D.40%
参考答案:B
I'm expecting a pet dog for long,but mom has no time to buy _________ for me.
A.it
B.one
C.this
D.that
哪些是中国式摔跤允许使用的动作如,().
A.跪撑
B.脚绊
C.手绊
D.抓握下肢