Question

the boys are sweating because they _____ (play) football for 3 hours.

Answer 1

The boys are sweating because they played football for 3 hours.

Detailed answer

Played is the most appropriate word to be used at this moment.

• The sentence is now a grammatically appropriate sentence that conveys  a special meaning
• The sentence now conveys that the boys were sweating because they were playing football for 3 hours.
• Any other word would create a sentence that is either incorrect or not grammatically appropriate.