sleep nine hours和sleep for nine hours两者都在文中见过,到底哪个是正确还是都正确,为什么,不应该家for吗

I sleep for nine hours every night sleep nine hours和sleep for nine hours两者都在文中见过,到底哪个是正确还是都正确,为什么,不应该家for吗 She sleep nine hours every night 对nine提问 i need nine hours' sleep every night.改为同义句 I never sleep for less than nine hours.中文是什么? You drink milk and sleep nine hours every i need nine hours' sleep every night.改为同义句 Studdents must sleep for about nine hours every night? i sleep nine hours every night.对划线提问（nine）______ ______ hours do you sleep every night? I sleep nine hours every night.(划线提问)划的是nine 5.Students ______ nine hours a day.A.sleeps B.sleep C.are sleep .Children should sleep nine hours every night.（对nine提问）______ ______ ________ _____children sleep every night? i sleep nine hours every night 划线提问______ ______ hours do you sleep every night?1.i sleep （nine hours） every night2.i sleep （nine） hours every night这两个划线提问一个划nine hours一个划nine二者有何区别分别该填 i sleep nine hours every night 划线提问______ ______ hours do you sleep every night?1.i sleep （nine hours） every night2.i sleep （nine） hours every night这两个划线提问一个划nine hours一个划nine二者有何区别分别该填什 I sleep nine hours every night.这句话表达正确吗?I sleep for nine hours every night.这两句没什么区别吗? Children should sleep for nine hours every night对for nine hours提问____ _____ time should children sleep erery night people need to sleep nine hours at least这句话有没有语法错误? we need to sleep eight or nine hours every night.为什么need后加to