at the picnic 还是 in the picnic啊?

at the picnic 还是 in the picnic啊? we had a great time at the picnic的at可以写成in吗 We(have are having)a family picnic in the garden at the moment 选哪个,为什么 at the picnic的汉语意思 在野餐 用at the picnic对吗? We're going to have a picnic 填on还是in还是for the holiday. in the library还是at the library? at the kitchen还是in the kitchen in the play 还是 at the play in the war 还是at the war at the party还是in the party? at the supermarket还是in the supermarket? in the hotel 还是at the hotel in the olypic game还是at the ... in the meeting 还是at the meeting in the park 还是 at the park at the community还是in the community ---at the evening 还是 in the evening