The present tense in Latin can be "sleep" or "are sleeping."
It's because there's no progressive tense.
In the audio, the accent on "pueri" is not correct. It sounds "puèri", like "ue" was a diphtong; but it's not. Instead, it should be "pùeri".
is the word "the" neceessary?
Yes and no. Both "the two boys sleep" and "two boys sleep" are correct English, so both answers should be accepted. They mean different things, and we aren't given the context that would tell us which is the accurate translation.