1. He opens his snack and eats it.
2. He opens his snacks and eat them.
3. He opens a bag of snack and eats it.
4. He opens a bag of snacks and eats cookies in it.
5. He opens a bag of snacks and eats cookies from it.
[Can we use all the sentences?]
1. OK
2. ... eats ...
3 -- no
4. ... eats the cookies ...
5 -- no