I think we should take care of the environment, so that we have something to leave for our children.
我觉得我们应该保护好自然,以便将来能给我们的子孙后代留下一些东西。
Historians have long been puzzled by dots, lines and symbols which have been engraved on walls, bones, and the ivory tusks of mammoths.
长期以来,历史学家一直对雕刻在墙壁上、骨头上、古代长毛象的象牙上的点、线和形形色色的符号感到困惑不解。