Mary's sister buys some fruit还是fruits?

Mary's sister buys some fruit还是fruits? You should eat some vegetables and fruits .用fruit 还是fruits. We want some fruit.和 He can eat fruits.为什么一个加S一个不加? Why don't we take some fruits?fruit不是不可数名词吗,为什么又加s? 这句英语对吗?let's go to fruit shop and buy some fruits some fruit 和some fruits哪个搭配是正确的? let's go to the fruit shop and buy some fruits.句中的buy可以加ing吗 Apples,bananas,pears and oranges are fruit 还是fruits? 是many kinds of fruits还是 many kinds of fruit oranges and apples are fruit(还是用 fruits) mary's sister's sister of mary's 那个对 3) Mary buys some bananas for her grandma.