What is a vital part of improving your grade?是什么意思

What is a vital part of improving your grade?是什么意思 They are a precious part of our cultural heritage--it is of vital importance that we do something.I 翻译“a vital part of a balanced ecosystem” What letter is a part of head? What letter is a part of vegetable? “What letter is a part of body? a vital what letter is a part of the head WHAT LETTER IS A PART OF THE HEAD? what letter is a part of the face? what letter is a part of body?是什么字母? What leter is a part of the head?为什么? 翻译What part of watermelon is used as a vegetable? What letter is a part of the face What letter is a part of the face? What letter is a part of our body? 英文智力问答what letter is a part of house? What is the most important part for a game?