Directions: Choose the appropriate modal to complete the sentence. If you want…

Answer: 'must'

Why this is correct:

• 'must' expresses strong necessity or obligation. In this sentence it indicates that hard work is required to gain knowledge.

• 'need' as a main verb can also express necessity, but it is normally followed by 'to' (you need to toil). The blank calls for a modal that fits directly before 'toil', so 'must' is more natural here.

• 'will' expresses future time, prediction, or willingness, not obligation, so it does not convey the required necessity.

• 'would' is used for hypothetical or conditional situations and does not state a present obligation.

Correct sentence: If you want knowledge, you must toil for it.