what kind of 后接单数还是复数?

what kind of 后接单数还是复数?
what kind of后接单数还是复数?初中课本和练习上有以下用法：
what kind of movies do you like?
what kind of noodles would you like?
what kind of fruit do you like?
what kind of job do you want?
what kind of book do you want?
到底什么时候用单数,什么时候用复数?