《广告原理》和《广告心理学》的出版标志着广告学的诞生。
参考答案：对
This book is ________ for a six-year-old boy to read. [ ]
A. enough easy
B. easy enough
C. easily enough
D. enough easily
流感嗜血杆菌通常分为几个型（）。
A.4个
B.5个
C.6个
D.7个
E.8个
