Though in fact he got      , there was no doubt that he had meant to offer help.

A．in a way

B．in the way

C．on the way

D．by the way

如果传染病病因不明确、传染来源一时调查不清，且无法获得有效的疫苗或预防性药物时，是传染病预防控制的关键措施（）

A、管理传染源

B、阻断传播途径

C、保护易感者

D、以上均正确