Question

 It must be done at any cost. (Identify the adverb phrase and write that as your answer)​

Answer 1

It most be done at any cost .

Answer 2

Explanation:

Here the adverb is must

An adverb is a word or a phrase that is used with a verb, adjective to highlight something related in terms of place, time, frequency, degree of that verb.

In the given sentence, work done is a verb and to stress it out, must be is added that's indicating the degree or importance of work

Other examples of adverb;

He ran abruptly.

She spoke in a harsh way