发生最早的免疫器官是（）
A.骨髓
B.胸腺
C.腔上囊
D.淋巴结
E.脾
参考答案：B
— Is there anything special you'd like for the dinner, Teddy?
— Nothing________, as usual, Mummy. [ ]
A. on the whole
B. in particular
C. in general
D. in total
