简答题What does the US Travel Association want to prove? A、Traveling makes you healthier. B、Chocolate and red wine are good for health. C、Some pleasurable experiences can be good for you. D、Having small quantities of some treats is good for health.简答题What is the purpose of the Travel Effect campaign? A、To develop American tourism. B、To promote the American economy. C、To encourage retired persons to travel. D、To change the way American view travel.简答题What do we learn about the Travel Effect campaign? A、It will finish in one year. B、It involves several studies. C、It is wasting a lot of money. D、It is the first project about traveling.