I don't know ____next.如何解释不填how to do?

i don't know ()to do.填what还是how 我不知道如何向他解释这件事.I don't know how to ( ) it ( ) ( ) 为什么I don't know what to do成立而I don't know how to do不成立 正常译法是i don't know what to do ,为什么不能用i don't know how to do i don't know how to do it句型转换 I really don't know ( )里面应该填what to do还是how to do,或者两个都可以? i don't know ---with the problem(填how to do 还是what to do ）.3 I don’t know what to do.I don’t know how to do.（ × ） 第二句 how i don"t know what to do (next) 和i don"t know how to do (next I don't know "What to do 和 I don't know "How to do it"?哪个句子是 I don't know how to I don't know how to say it in english How to do