The ancestral apes already had large and high-quality brains.They had good eyes and efficient grasping hands.They inevitably had...

Do you like animal? What’s your favorite animal? My favorite animal is monkey. It is lovely and clever. People always say that our human beings ar...

大约在4亿年前的泥盆纪，地球上的淡水湖泊和沼泽里生活着数量很多的总鳍鱼。这种鱼的身体呈纺锤形，游动速度很快，是一种肉食性的鱼。到了泥盆纪末期，地球上...