People often have the belief ________a healthy environment and development cannot be possible at the

same time, but this does not have to be true.[ ]

A. that            

B. which              

C. where            

D. what

X线下见右下肺出现大片的浓密阴影，其内见一个含有液平面的圆形空洞，洞内壁光整，洞壁较厚。应首先考虑的是（）。

A.肺大疱

B.肺脓肿

C.浸润型肺结核空洞形成

D.慢性纤维空洞型肺结核

E.周围型肺癌空洞形成