冠状动脉狭窄段直径减少9／10为（）
A.75%狭窄
B.80%狭窄
C.85%狭窄
D.90%狭窄
E.95%狭窄
参考答案：D
I began to teach English _______.
A. for two years
B. three years ago
C. in two years
D. three years before
中医学上，被称为人体"气机升降之枢纽"的两个脏是（）
A.肺、肾
B.心、肾
C.肝、肺
D.脾、肺
E.脾、胃
