28. Alone in a deserted house, he was so busy with his writing that he felt ________ lonely.

A．nothing but

B．anything but

C．all but

D．everything but

国家颁布的哪个标准对办公建筑物空气质量提出了具体要求（）。

A.《大气卫生标准》

B.《大气环境质量标准》

C.《住宅卫生标准》

D.《室内空气质量标准》

E.《办公建筑物卫生标准》