-Are you familiar with the music?

-Yes. There was a time _____ this kind of music was quite popular.

A．that

B．when

C．with which

D．about which

处于人口密集区的施工现场，禁止()

A.向大气排放含有毒物质的废气

B.焚烧沥青

C.向大气排放粉尘

D.适用产生恶臭气体的物质