The city is believed      over by sandstorms from AD200 to AD400.

A．to cover

B．to be covered

C．to have been covered

D．that was covered

合胞病毒肺炎（）

A.柯萨奇A组病毒

B.流感病毒

C.肺炎支原体

D.呼吸道合胞病毒

E.腺病毒3、7型