单项选择题
A.大叶肺炎 B.休克 C.胆管阻塞 D.猩红热
A.苍白B.发红C.发绀D.色素沉着
A.30-50cm,20-30min B.30-50cm,30-60min C.50-60cm,20-30min D.50-60cm,30-60min