Dashan        Chinese since he came to China. He speaks good Chinese now.

A. learned        B. has learned     C. learns

肺动脉栓塞更易发生于（）

A.右侧和下肺叶

B.左侧和下肺叶

C.右侧和上肺叶

D.左侧和上肺叶

E.全肺