有一道英语作业不会做!请大家帮帮忙!

有一道英语作业不会做!请大家帮帮忙!
句型转换.根据题后要求变换下列各句,每空一词.
1.Half an hour ago, Harry Potter began.(改为同义句）
Harry Potter has _____ _____ for half an hour.
2.Both of the twins have been to Beijing.(改为否定句）
_____ of the twins _____ been to Beijing.
3.Mr Black borrowed the book from the library the day before yesterday.(改为同义句）
Mr Black _____ _____ the library book for two days.
4.Mike has already had dinner.(改为否定句）
Mike _____ _____ dinner _____.
5.Harvey enjoyed himself very much at Water World.（改为同义句）
Harvey _____ a _____ _____ at Water World.
感谢感谢感谢!