let sb do 为什么不是let sb to do?

let sb do 为什么不是let sb to do? let sb to do sth 对吗?为什么 let sb to do 还是let sb do let sb do sth还是let sb to do sth let sb.do sth.or let sb.to do sth Let sb do. let sb do let sb do sth let sb·do let sb doing 为什么Allow sb to do sth,Ask sb to do sth就有to,而Let sb do sth ,H let sb to do sth怎么造句 let sb to do 中文意思