It's a good idea to eat a lot of fruit and vegetables every day? We couldn't keep on cleaning the streets because it rained heavily? The garden party won't take place if the weather doesn't improve

1. It's a good idea to eat a lot of fruit and vegetables every day.
We should
2. We couldn't keep on cleaning the streets because it rained heavily. (so)
It
3. The garden party won't take place if the weather doesn't improve.
Unless
4. Both students and teachers can borrow books from the library.
The library lend
5. Nobody plays this piece of music as beautifully as he does.
He plays this