20．We met _____ and have become good friends since then.

A. by mistake　 　　　 B. by accident　 　　 C. by ourselves　 　 D. by the way

19．_____ your advice, I’m sure to consider it and give you reply in time.

A. In spite of　 　　　　 B. But for　 　　　　　　　 C. Because of　 　　 D. As for