不属于外周免疫器官的是（）
A.胸腺
B.淋巴结
C.肠相关淋巴组织
D.脾脏
E.黏膜相关淋巴组织
参考答案：A
There is a bird _____ the tree. [ ]
A. in
B. on
C. to
D. of
To those disabled athletes, the most important thing is _______ win a gold, ______take part.
A．not only; but also
B．either; or
C．both; and
D．not to; but to
