[解析]
M:The kids are at their grandma's house.so Are you ready for the party at Betsy's house tonight? W:Now,it's not even five. M:Betsy said we should arrive before dinner. W:We still have time. Betsy said she would serve the food around seven. And you know her She never does anything early. M:Yeah,that's true. But it takes an hour to get there on the subway. Why don't we try to get there at6:40? W: 6:40 sounds good. But let's just take a taxi it'll only take 30minutes. AB