答案如下：
1.They have been here since 2000.(对划线部分提问）
How long have they been here?
2.The old man died last year.He has been dead for a year.(die)（动词填空）
3.This factory opened twenty years ago.(同义句转换）
This factory has been open for twenty years.
4.Miss Gao left an hour ago/(同义句转换）
Miss Gao has been away since an hour ago.
5.Her mother has been a Party member for three years.(同义句）
Her mother joined the party three years ago.
6.The Green Family moved to France two years ago.(同义句转换）
It's two years since the Green family moved to France.
7.The bus has arrived here.It arrived ten minutes ago.（把两个句子合并成一个句子）
The bus has been here since ten minutes ago. 答案如下：
1.They have been here since 2000.(对划线部分提问）
How long have they been here?
2.The old man died last year.He has been dead for a year.(die)（动词填空）
3.This factory opened twenty years ago.(同义句转换）
This factory has been open for twenty years.
4.Miss Gao left an hour ago/(同义句转换）
Miss Gao has been away since an hour ago.
5.Her mother has been a Party member for three years.(同义句）
Her mother joined the party three years ago.
6.The Green Family moved to France two years ago.(同义句转换）
It's two years since the Green family moved to France.
7.The bus has arrived here.It arrived ten minutes ago.（把两个句子合并成一个句子）
The bus has been here since ten minutes ago.