I have some doubt ____ his words, but _______ is no doubt that he has passed the exam.

A．about; it

B．of; that

C．about; there

D．to; he

大剂量碘剂不能单独用于甲亢治疗的原因

A．引起慢性碘中毒

B．失去抑制甲状腺激素合成的效应，诱发甲亢

C．使腺体血管增生，腺体增大

D．使T3转化为T4

E．为甲状腺素合成提供原料