[观察例句]
1．The train has been racing along steadily since it left Xining.
2．All this time，the song “Sky Railway” has been playing inside my head.
3．Wild animals such as these Tibetan antelopes have now been using these passages for years.
4．The journey has been flying by，and before I know it，we have reached Tanggula Station.
5．The QinghaiTibet Plateau has been attracting people's admiration for centuries.
