节细胞神经瘤常发生在（）
A.听神经
B.皮肤
C.胸膜
D.后腹膜
E.后纵隔
参考答案：E
Our new English teacher , who is said to have moved back to China, _______ in America for almost ten years.
A．lived
B．has lived
C．was living
D．had lived
免疫球蛋白的基本结构组成包括（）
A.两条重链和两条轻链
B.两条重链
C.两条轻链
D.F（ab’）与Fc段
E.Fab与Fc段
