—May I listen to the music here, Mr. White?

—Sorry, you’d better         it like that.

A．not to do

B．not do

C．don’t do

D．not do to

悬挑脚手架型钢宜采用双轴对称截面的型钢，一般采用的是（）。

A.槽钢

B.等边角钢

C.H型钢

D.工字钢