I       lunch when I learned that former British prime minister Margaret Thatcher had passed away.

A．ate

B．had eaten

C．was eating

D．were eating

静脉注射腺苷治疗阵发性室上性心动过速时，以下何种情况禁用（）。

A.低钾血症

B.病窦综合征

C.心力衰竭

D.冠心病心绞痛

E.高血压