脑筋急转弯。

1. What weather do mice and rats fear?

   Answer: _____                                                                

2. When do dogs refuse to follow their master?

   Answer: _____                                                                

周围免疫器官包括（）

A．胸腺、脾、黏膜组织

B．腔上囊、脾、扁桃体

C．骨髓、淋巴结、脾

D．脾、淋巴结、黏膜相关淋巴组织

E．扁桃体、骨髓、淋巴结