13. Command
14.A
15. B.
16. C
17. I'm not positive on this one. However, I am going to guess run on simply because they're should have not been a and in between.
No, grandparents is a common noun, therefore you don't capitalize it. It would be different if you had the names of the grandparents. Like if your grandma is named Martha. You would have to capitalize their name since it is a proper noun
It would have to be the gasoline manufacturers because an electric car would run on electricity not gasoline
There would be 11 bananas. You would add six and five together.
