新概念4的句子19课
Itisfairlyclearthatsleepingperiodmusthavesomefunction,andbecausethereissomuchofitthefunctionwouldseemtoeimportant.1somuchofit这里的it指的什么2of去掉不行吗3还有it和the之间难道不需要标点符号隔开吗