in和on和by的區別和用法

　　They crossed the river by ferry.

　　他們乘渡船過了河。

　　They paid in cash.

　　他們用現金支付。

　　Did you hear it on the radio?

　　你是從收音機聽到這消息的嗎？

　　Now I can walk to work instead of going by car.

　　現在我可以步行去上班，而不必開車了。

　　In our company, quality is high on the agenda.

　　我們公司高度重視質量。