Please read through the following versions, and then indicate which versions you think are grammatically correct:
1. Time flies like an arrow, fruit flies like bananas.
2. Time flies like arrow, fruit flies like banana.
3. Time flies like arrows, fruit flies like bananas.
4. Time flies like an arrow, fruit flies like a banana.
5. Time flies like the arrow, fruit flies like the banana.
6. Time flies like the arrows, fruit flies like the bananas.
7. Time flies like arrows
, fruit flies like the banana.