通常情况下,载体应连接多少个以上半抗原才能使动物有效产生抗体()
A.25个
B.20个
C.35个
D.30个
E.15个
参考答案:B
若M是ⅡA族的某元素,则与M同周期且相邻的元素不可能位于元素周期表的
A.ⅠA
B.ⅠB
C.ⅢA
D.ⅢB
There is no way to get to the small island where my grandparents live _____ by boating. [ ]
A. rather than
B. other than
C. instead of
D. in place of