gathering data from the oceans,which(cover)percent of the earth's surface is important to(understanding)climate change为什么不是covers/be understood

gathering data from the oceans,which(cover)percent of the earth's surface is important to(understanding)climate change为什么不是covers/be understood
gathering data from the oceans,which(cover)percent of the earth's surface is important to
(understanding)climate change
为什么不是covers/be understood

gathering data from the oceans,which(cover)percent of the earth's surface is important to(understanding)climate change为什么不是covers/be understood
which引导的定语从句 先行词是oceans,复数,所以从句谓语用cover,不加s