giant dinosaurs may have no longer roamed the forest, 巨大的恐龙也许不再主宰森林
whose ancestors once roamed on land. 它的祖先曾遍布陆地
In summer, bison roamed freely, 夏季 美洲野牛四处漫步
three hundred thousand blue whales roamed the oceans 30万头蓝鲸让海洋看上去充满生气