The difference between must and must:

(1) must be followed by a verb and a noun.

(2) They have different meanings: they must be [b] to indicate that they are necessary in fact and sense. There must be [b] there must be; It is indispensable.

(3) Both are mandatory: they must be mandatory. Necessity is subjective urgency.

Usage: "must" is an adverb, emphasizing that something must be done this way; "Necessary" is a verb that emphasizes the special need of something.

Extended data:

It must have something to do with famous sayings

(1) People should have patience, especially confidence. Madame Curie

(2) Learning without learning is useless, and using without learning is dull; Learning and application must be combined, and both are indispensable. Zhou Haizhong

(3) You can use any language when purchasing; But when selling, you must use the buyer's language. Margaret Spellings

English-Chinese translation

Something must be done. Something must be done about it.

(2) The play must be edited many times before it is broadcast. The play must be abridged several times before it is broadcast.

(3) Children's furniture must be able to withstand punching and kicking. Children's furniture must withstand punching and kicking.