公称外径为40mm的PP-R管,采用热熔连接的加热时间为12s。( )
参考答案:对
How happy we were each other !
A.to see
B.seeing
C.saw
D.have seen
A: Well, Mrs. Anderson, I’ve completed my examination and I’m happy to say that there’s nothing serious. B: __________________
A. Well, is the examination difficult for youB. Don’t you think I should have X-raysC. Oh, I don’t believe it.D. Are you sure that your examination is correct