go on a picnic和have a picnic什么区别啊?

go on a picnic和have a picnic什么区别啊? go on a picnic和have a picnic意思一样吗? go on a picnic等于have a picnic,have a trip等于take a trip go on a picnic 和go for a picnic那个对? ＿,we shall go on a picnic 【去野餐】到底是go on a picnic呢还是 have a picnic呢还是 go for a picnic呢还 On Saturdays they（ ）have a picnic have a picnic和have picnics有什么区别?怎么用 词组：have a picnic to have a picnic have a picnic have a picnic是什么意思