To be honest, if it were not for the fact that you ____ my close friend, I would not take such pains

to serve you. [ ]

A. were

B. are

C. had been

D. have been

六氟化硫气瓶的搬运和保管，应符合下列要求（）

A.六氟化硫气瓶的安全帽、防振圈应齐全，安全帽应拧紧。

B.六氟化硫气瓶应采用人工搬运。

C.六氟化硫气瓶应存放在防晒、防潮和通风良好的场所。

D.六氟化硫气瓶不得与其他气瓶混放。