Some of us fail to learn that pain is the body’s way of informing the mind ______ we are doing something wrong, not necessarily ______ something is wrong.

A．that, what

B．that, that

C．what, that

D．what, what

液化石油气瓶如果是产品铭牌缺少，而造成瓶体自重不清应（）处理。

A.参照同一型号气瓶的重量；

B.按照平时的充装经验确定充装量；

C.不能充装