《药学学报》属于（）
A．一次文献
B．二次文献
C．三次文献
D．主动的药物信息服务
E．被动的药物信息服务
参考答案：A
对于现浇混凝土井壁，其局部厚度偏差不得小于设计厚度()mm。
A.30
B.40
C.50
D.70
Study the following paragraph carefully and write a letter in at least 100 words.
On September 9, 2004, Li Jin who is a student of Tsinghua University posed an offer to the Office of Graduate Admissions of Boston University. As an officer in it, you should write back to him.
