Wow. You are learning ancient Chinese prose? Do you think it is hard? We are required to recite a lot of ancient Chinese prose/poems at school. Hehe. Now I almost forget a lot. I am not sure if there is any difference here. To explain it in English, the sentence means How do I know if some people from our country will betray our country and reveal the condition of our country to the state Zheng? 庸 means 何，怎么 (kinda similar to HOW in English) Hope it helps. :)