Americanslikemanypeopleelsewhereintheworldliketoinvitefriendstotheirhomesfortheeveningoffood,drinkandconversation.Formaldinnersinfinehomesand(hotels)intheUSaremuchthesameasformalformaldinnersanywhereintheworld.ButasmostpeopleintheUShavenoservants,theirdinner(parties)athometendtobeinformal.Guestsmaysitdownatatableorasmanynewsmallhomeshavenoseperatediningroomorverysmalldiningspace,guestscanalsoserve(themselves)andeatinthelivingroom,holdingtheirplatesortraysontheirknees.

　　Amore(enjoyable)formalentertainmentisthepicnic.Americansaregreekpicnickers,andalmosteveryfamilyhasapicnic(basket).Summerinvitationsareoftenforapicnicataparkorinthe(open)countryside.Unlesshamburgersorhotdogsarecookedoverthefire,picnicfoodisusually(cold).括号里的是答案