相關Todaythereare6billio的文學知識

問題詳情：   Todaythereare6billionpeopleontheearth.Bytheyear2050theremaybe12.5billion.Thisisalotofpeopletofeed.Weneedmorefood.   Onewaytoproducemorefoodisbygrowingstrongerplants.Forthousandsofyear...