Topics: Modal Verbs

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In most developed countries,it is not necessary for people to boil water before they drink it.

A. In most developed countries,people ought to boil water before they drink it.

B. In most developed countries,people must boil water before they drink it.

C. In most developed countries,people needn’t boil water before they drink it.

D. In most developed countries,people mustn’t boil water before they drink it.