现在完成进行时
[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.
[归纳用法]
1．现在完成进行时的构成
现在完成进行时是由“have/has been＋现在分词”构成的。
He is ill.He's been lying in bed for three weeks.
他病了。已经卧床3个星期了。
Your eyes are red.Have you been crying?
你眼睛红了。你刚刚哭过了吗？
What have you been doing all this time?
这半天你干什么来着？
