When you do not have enough time to complete your homework, that time is: sufficient
abundant
inadequate
adequate

inadequate

Explanation:

Among the choices above, it is only the word "inadequate" that refers to lack of time or having not enough time. The context clue here is the prefix "in," which means "not." In this case, it means "not adequate."

The word "abundant" means that the person has a lot of time or more than enough time that was given to him. The words "sufficient" and "adequate" means that the time was just enough to complete the homework.

answer; they burn down the bushes and trees;