断面淡红棕色或黄棕色，显颗粒性，髓部有星点的药材是（）
A.黄连
B.虎杖
C.何首乌
D.黄芩
E.大黄
参考答案：E
He finds _____ really difficult for him to learn English well in just one year. [ ]
A. that
B. this
C. it
D. its
所谓心理卫生问题就是平常说的毛病，或是不正常的行为。
