下列耳鼻喉科疾病中，“头痛是此病区别于鼻炎的典型表现”为（）
A.鼻炎
B.急性扁桃体炎
C.急性喉炎
D.慢性咽炎
E.急性化脓性鼻窦炎
参考答案：E
It's very cold outside. You'd better _____ your coat when you go out. [ ]
A. dress
B. put on
C. wear
D. have on
对是个处理组、b个随机区组的资料进行方差分析，其误差的自由度为
A．kb-k-bB．kb-k-b-1C．kb-k-b-2D．kb-k-b+1E．kb-k-b+2
