[观察例句]
观察下列句子，并指出黑体部分的时态及语法作用
1．He has been writing a novel，which will be finished next month.
现在完成进行时 表示未完成的动作
2．He has written a novel，which is being prepared to come out now.
现在完成时 表示动作已经完成
3．I have been visiting my hometown recently，and it impresses me differently each time.
现在完成进行时 表示动作的重复
4．I have visited my hometown recently，whose changes have left a deep impression on me.
现在完成时 表示一次性动作
5．Recently she has always been helping me.
现在完成进行时 具有感情色彩
6．Recently she has helped me a lot.
现在完成时 陈述一种事实
