焊缝缺陷对压力容器有哪些危害?
参考答案:
(1)破坏了焊缝的连续性,降低了焊接接头的机械性能;
(2)引起应力集中;
(3)缩短使用寿命;
(4)造成脆断,危害安全。
编制频数表时,组距常为
A.极差的1/20B.极差的1/10C.极差的1/5D.以上均不是
—You've got a cold, not the H7N9! Everything will turn out OK.
—______! I have been worrying about it for days.
A.What a relief
B.That's for sure
C.How surprising
D.I'm sorry to hear that