寒邪的致病特点是（）
A.阻遏气机升降
B.导致气机收敛
C.易生风动血
D.多易伤肺
E.易于引起流行
参考答案：B
My mother was cooking while I________ the radio. [ ]
A. listened to
B. have listened to
C. was listening to
D. is listening to
黄龙玉又可称为（）
A.玉石
B.天然玉石
C.人工玉石
D.石英岩
