A number of cases will be discussed at the meeting by the students   beginners of

English fail to use the language properly．

A．which

B．as

C．why

D．where

下列疾病中，应禁用β受体阻断药的是

A．心绞痛

B．房室传导阻滞

C．快速型心律失常

D．高血压

E．甲状腺功能亢进