A．( Because they may not judge speeds very well

B．( Because they may step into the road for convenience

C．( Because they cannot run very fast

D．( Because they may become nervous easily

以下哪项不是二尖瓣球囊成形术的适应证（）

A.重度二尖瓣狭窄，心功能Ⅲ级

B.瓣叶轻度钙化

C.外科分离术后再狭窄

D.合并左心房内血栓

E.合并轻度二尖瓣关闭不全