Fill in the blanks using the correct tense of the verbs given in brackets. Jack ______(complete) his homework before the teacher arrived 

Explanation:   Had completed (correct tense): In this context, the past perfect tense "had completed" is appropriate as it indicates that the completion of Jack's homework occurred before another past action (the teacher arriving). Options:   (a) Completed: This is the past tense, but it doesn't convey the necessary chronological sequence of events. It suggests completion without specifying its relationship to the teacher's arrival. (b) Complete: This is the base form of the verb and does not convey the correct past tense. (c) Completes: This is the present simple tense and is not suitable for describing a completed action before another past action. (d) Had completed: This is the correct past perfect tense, indicating that the homework was finished before the teacher arrived.