Although ______ for many years, the two old sisters recognized each other at once.

A．having been separated

B．being separated

C．having separated

D．had been separated

与药物效应强弱有关的药动学过程是：

A．药物消除的速度

B．血浓维持的时间

C．药物吸收的程度

D．药物吸收的速度

E．药物的达峰时间