Haveyouevernoticedadvertisementswhichsay“Learnaforeignl...
问题详情：Haveyouevernoticedadvertisementswhichsay“Learnaforeignlanguagein6weeks,oryourmoneyback!Fromthefirstdayyourpronunciationwillbeexcellent.Justsend…”andsoon?Ofcourse,itneverhappensquitelikethat...