Robert is said ___________ abroad, but I don’t know what country he studied in .

A．to have studied

B．to be studying

C．to study

D．to have been studying

β受体阻断药的适应证有（）

A.高血压

B.心律失常

C.心绞痛

D.房室传导阻滞

E.甲状腺功能亢进