what to do和how to do it为什么前者不能加it而后者必须加?

how to do和what to do的区别 WHAT TO DO=HOW TO DO how to do it和what to do it的区别how to do it，what to do 的区别 how do you what to be adj what/how to do 句型be adj what/how to do 和 do what/how to do 一样么 就是系表后不用带介词? what to do和how to do She feels sad.She doesn't koow ______________.A what to do B how to do it how to do it next还是what to do next 关于how to do it what to do what to do how to do it区别 How to do What to do.的用法 how to do it what to do的区别 I want to learn______ a.what to do with it b.how to do c.what to do it d.to do 写出原因 用what和howI want to learn______ a.what to do with it b.how to do c.what to do it d.to do 写出原因 用what和how分别怎么问 what to do和how todo的区别 l really don,t know _____ and _____.A.What to do,How to do B.what to do it ,how to do itC.what to do it ,How to do D.What wo do,how to do it how to do,how to do it,what to do 有何区别? how to do,what to do,what i can do的用法how to do,what to do,what i can do怎么使用? how to do the next和what to do next这两句句子对吗? what to do 和how to do it 的语法要点