It doesn’t matter ________ you take it seriously, for _______ matters is that he can realize it.

A．whether; that

B．that; what

C．whether; what

D．that; that

按管道设计压力分类，中压管道一般指（）的管道。

A.1.6≤p＜6.4Mpa

B.1.6≤p＜8Mpa

C.1.6≤p＜10Mpa

D.1.6≤p＜12Mpa