because scientists discovered the remains of their bones when they dug underneath the ground. We can see the skeletons of these dinosaurs now in the museums.嗯，本人水平有限，也就这样了。
Millions of years ago, the dinosaurs(恐龙) ruled the earth. Since then, there have been no dinosaurs. What happened to then? We know they did not all die at once. It may have taken a few million
小懒虫苗啊苗
