初次免疫应答产生的免疫球蛋白是（）

A.IgA

B.IgG

C.IgM

D.IgD

E.IgE

改错题。

1. Although we are not in the same school,but we are still good friends._____

2. I would be such tired that I would want to go back home._____

3. He is so young to go to school._____

4. He got up too late that he missed the school bus this morning._____

5. Tom was ill so that he didn’t go to school._____