The boy said ___ couldn't he work out the problem but his teacher didn't know how to do it.

A．though　

B．never　

C．hardly

D．not only

有较强的消毒作用和镇痛作用，对牙髓的刺激性小

A．木榴油
B．樟脑酚合剂
C．70%～75%乙醇
D．甲醛甲酚
E．麝香草酚酒精溶液
与以下所描述性质相符的药物是