I cannot forgive myself for not seeing my mother when she was sick in bed.
母亲病的时候我没能去看她,为这件事我永远不能原谅我自己。
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。