when什么时候? when will you be back? in 3 days. how long 多长时间 how long does it take for going home? 3 hours how soon 多快 how soon can I take my card back? in 3 days（这种情况也可以用when!）
when是指什么时候 When are you going school ? In fine doy. haw lang 多长时间 Haw long is it tates you for your home to school? About tow hours. hao soon 多快；与"when”相同...
