necessary的名詞形式是什么

　　necessary和necessity的例句

　　For her, books were as necessary to life as bread.

　　對她來說，書就像面包一樣，是生活必需品。

　　If necessary, you can contact me at home.

　　必要的話，我在家時你也可以和我聯(lián)系。

　　If necessary I can come at once.

　　如果有必要，我可以馬上來。

　　There is agreement on the necessity of reforms.

　　對改革的必要性已經(jīng)達成了共識。

　　The article proves the necessity of reform.

　　文章論證了改革的必要性。

　　I often drop into the store for some daily necessities.

　　我常光顧那家小店買些日用品。