对所有癫癎类型都有效的广谱抗癫癎药是（）

A．乙琥胺

B．苯巴比妥

C．丙戊酸钠

D．苯妥英钠

E．硝西泮

There was a time_____we went to the country and stayed with the farmers there.  

A．which

B．that

C．when

D．while