Question

something must be done for us (tag question )​

Answer 1

Question tag to the given sentence can be added as shown below:

Something must be done for us, mustn't it?

A tag question is a question added at the end of a sentence. A tag question following an affirmative statement generally has the form of a negative question and a negative statement has an affirmative question, with the meaning: Isn't that true? A question tag always consists of the helping verb of the tense and the pronoun used in the main clause.

Answer 2

Answer:

something must be done for us