Sometimes it's not_to know the parts of a new word to understand it,but it will help you many times
问题描述：
Sometimes it's not_to know the parts of a new word to understand it,but it will help you many times
Sometimes it is not__ to know the parts of a new word to understand it,but it will help you many times.
为什么要填enough?helpful和useful不可以吗?
答
不能用helpful
be helpful to + sth.如果是动词的话,应该用动词的现代分词形式及do+ing.
句意：
有时候知道一个新单词的一部分字母对理解它的意思是不够的,但大多数情况都能帮助你（理解单词的意思）.