对于外径大于28mm压缩天然气管道,其连接应采用( )方式。
A.焊接 B.法兰 C.双卡套接头 D.螺纹
参考答案:A
罪犯劳动保护的范围包括哪些?
A whipping is().
A.a messenger
B.a stopper for nylon line
C.a U-bolt for securing a cargo whip to the winch drum
D.turns of twine around a rope end