Do you know when to have a picnic?为什么用to have?

Do you know when to have a picnic?为什么用to have? Do you know when to have a picnic? -Mike wants to know if you ()(have)a picnic tomorrow. we're going to have a picnic this afternoon.为什么要用have不用do? to have a picnic Tom wants to know if---have a picnic tomorrow. 25.Tom wants to know if you will have a picnic tomorrow.Yes. do you know什么at8:00am a：who to talk wath b：when to have a me When and where to have a picnic yet When are you going to have a picnic该怎么回答 求翻译：why do you care to know when you are not going to have s do you like to have a picnic 这句话的答句