solemn的名詞形式是什么

　　例句：

　　I made a solemn promise that I would return.

　　我鄭重承諾我會(huì)回來的。

　　His behaviour was not in keeping with the solemn occasion.

　　他的舉止與這莊嚴(yán)的場(chǎng)合不協(xié)調(diào)。

　　This is a solemn curtsy in the party.

　　這是一個(gè)在聚會(huì)中的隆重的禮節(jié)。