You don't have to worry about him
必要───necessary;担心───worry
He believed that in building socialism it was necessary to make thorough plans on behalf of the state.───他认为搞社会主义,要替国家好好打算盘.
They always sum up their ( work ) experience whenever it is necessary, so they improve rapidly.───他们总是随时总结经验, 所以工作质量提高很快.
It is necessary to decrease the amount of coal used.───必须减缩用煤量.
They are only doing what is necessary to prevent wholesale destruction of vegetation.───他们只是在采取必要措施避免大规模的植被破坏。
It is necessary to exercise caution when making commendations.───做推荐时有必要谨慎一些.
Hospital admission is not necessary in most cases.───大多数情况下，病人无须住院。
to go through all the formalities necessary in order to get a gun licence───办理取得持枪执照的全部必要手续
For her, books were as necessary to life as bread.───对她来说，书就像面包一样，是生活必需品。
If God did not exist, it would be necessary to invent Him.
Knowledge is a comfortable and necessary retreat and shelter for us in an advanced age; and if we do not plant it when young, it will give us no shade when we grow old.
My money came short of the necessary sum.
To travel through the world it is necessary to have the mouth of hog, the legs of a stag, the eyes of a falcon, the ears of an ass, shoulders of a camel, and the face of an ape, and overplus, a satchel full of money and patience.
Attractive label is very necessary.