属于异黄酮类的是（）
A.黄芩苷
B.芦丁
C.葛根素
D.橙皮苷
E.甘草素
参考答案：C
We wanted to know _____. [ ]
A. where did he live three years ago
B. where he lived in three years before
C. why he cried so sadly
D. how soon he will come back
关于听力的叙述，错误的是
A．人耳能感受的振动频率在16～20 000HｚB．入耳最敏感的声频是1000～3 000HzC．耳的适宜刺激是空气振动的疏密波D．能够引起听觉的最小声频称为听闻E．表示声音强度的常用单位是dB
