英文tense問題!!!!!!

1a:If I were you,I ____(not eat)so many sweets.
2a:I think I will go fishing tomorrow.____you____(want)to come with me?
3a:Alice is a writer.She has worked hard for three days.She___(write)a book on aliens.
4a:I ___(see) this lovely picture before.I like it very much.
5a:If I were a shark,I ___(not eat)fish.

唔該你地-.-.-