conversation對話可數嗎

　　I had a long conversation with her the other day.

　　前幾天我與她作了一次長談。

　　The main topic of conversation was Tom's new girlfriend.

　　交談的主要話題是湯姆的新女友。

　　Don was deep in conversation with the girl on his right.

　　唐與他右邊的女孩在專心交談。

　　I don't know how to make polite conversation.

　　我不曉得怎么說應酬話。

　　I couldn't hear their conversation through the wall.

　　我隔墻聽不到他們的交談。