You know that you … it before tomorrow.

Analyze the question: The sentence is "You know that you ____ it before tomorrow." The blank needs a verb phrase that fits a statement about something you know, and that is tied to a deadline ("before tomorrow").

Explain the concept: Modal verbs express different meanings:

• might / may express possibility ("you may do it" means perhaps you will).
• ought to expresses duty, obligation, or strong advice (something that is right or necessary to do).
• like to expresses preference, which does not fit a deadline.

Test each option:

• A. might do: "You know that you might do it before tomorrow." This expresses only a slight possibility. It is odd after "You know that", because we do not "know" a mere possibility in this way. Also, "do it" needs a clear sense of obligation here.
• B. ought to do: "You know that you ought to do it before tomorrow." This is natural. The speaker is reminding the person of a duty with a deadline, and "know that you ought to" is a common pattern.
• C. like to do: "You know that you like to do it before tomorrow." This makes no sense with a deadline and is not idiomatic.
• D. may do: "You know that you may do it before tomorrow." This expresses permission or possibility, which is weaker and less logical after "You know that".

Answer: The best choice is B. ought to do, because the sentence expresses an obligation to complete a task before a deadline.

Tip: When a sentence has a deadline such as "before tomorrow", "by Friday" or "before the exam", think of obligation words: ought to, should, must, have to. Use may/might only when the sentence is about possibility or permission.