激动β受体同时阻断α受体可导致的效应是（）
A.血管扩张
B.瞳孔散大
C.支气管扩张
D.心率加快
E.心传导加速
参考答案：A, C, D, E
Mike wasn’t at home yesterday. He ______to give us a lecture.
A．is inviting
B．is invited
C．was inviting
D．was invited
