正常气管隆突的分叉角度约为（）
A.45°～75°
B.55°～85°
C.65°～90°
D.60°～85°
E.60°～75°
参考答案：D
She was amazed by in the mainland at the age of 6. [ ]
A. what she saw
B. what did she see
C. where she saw
D. where did she see
下列各项，可致人群对某种传染病易感性增高的是（）。
A.该传染病流行过后
B.人群中一般抵抗力的提高
C.人群中自动免疫的推广
D.病原体的变异
E.抗生素的广泛应用
