下列哪项是抗原与抗体的结合部位?()
A.CH4
B.CH1
C.CH2
D.CH3
E.VH/VL
参考答案:E
There are three reading-rooms in our new library, _______about four hundred students in all.[ ]
A. seating
B. sat
C. seated
D. sitting.
深基坑开挖时,应对()等经常进行复测检查。
A.地基承载力
B.平面控制桩
C.水准点
D.水平标高
E.边坡坡度