药物的安全性指标是( )。

A．LD₅₀/ED₅₀

B．ED₅₀/LD₅₀

C．LD₅₀

D．ED₉₅与LD₅之间的距离

E．LD₉₅与ED₅之间的距离

On average, a successful lawyer has to talk to several（）a day.

A.customers

B.supporters

C.guests

D.clients