SHOULD_SHOULDN'T
If someone doesn’t speak your language very well, you ____________ speak fast; you ___________ speak slowly and carefully.
shouldn't - should
If you need a pen, you ____________ say ‘Give me that pen’; you ___________ say ‘Could I borrow your pen, please?’
shouldn't - should
If people want to live until they’re very old, they _________ eat a lot of fruit and vegetables; they ________ eat a lot of cakes and chocolate.
should - shouldn't