water will contiue to be _it is today next in importance to oxygen.空上是填what还是which,为什么?
问题描述：
water will contiue to be _it is today next in importance to oxygen.空上是填what还是which,为什么?
答
what表语从句
Water will continue to be （what it is today next in importance to oxygen）.今后,水将依然处于仅次于氧气的重要地位.