--Look! The telephone is broken. Someone damaged it ________ purpose.

--That may be right. But perhaps it was broken _________ accident.

A．on; by

B．by; by

C．on; on

D．by; on

老年人口服苯巴比妥吸收减少是因为

A．胃pH升高，离子型药物增多
B．胃pH升高，转化率变慢
C．胃排空速度减慢
D．肠排空速度加快
E．肝血流量减少，首过效应减弱