We need to set about a solution.[ ]
A. to find
B. to finding
C. finding
D. find
答案:C
肺门舞蹈征象最常见的先天性心脏病是
A.室间隔缺损B.房间隔缺损C.动脉导管未闭D.法洛四联症E.肺动脉狭窄
岩石破碎机理