strengthened to prevent silica in the grass from wearing them out... 能够防止草中的二氧化硅磨损牙齿
But the endless plains were no paradise for the mammals. 但无尽的平原并不是哺乳动物的天堂
it would soon cover one-fifth of the land. 不久将覆盖五分之一的陆地
Taking root during the great drying... 草在大干燥时期扎根
there rose from the ashes a life-form that had previously only survived 一种此前只在边缘地带幸存的生物
clearing the way for something completely different... 为一种完全不同的东西铺平了道路