请给位为我解答一下英语题吧!谢谢了 1.Jerry has to work hard to feed his large

请给位为我解答一下英语题吧!谢谢了 1.Jerry has to work hard to feed his large family(改为否定句）
Jerry ____ _____ to work hard to feed his large family
2.Henry put on his scarf before he left the coffee（改为否定句）
Henry _____ _____ on his scarf before he left the coffee
3.Unless you clean your teeth requlary,you will get toothache.(同义句）
_____ you ____ clean your teeth regulary.you will get toothache.
4.We must put this warning sign outside the gate of the museum.（改为被动语态）
This warning sign must_____ ______ outside the gate of the museum.
5.Two pandas from China will stay in a British 200 for ten years.(对划线部分提问划线部分是for ten years）
______ ______ will two pandas from China stay in a British zoo?
6.Fresh water is limited（有限的).We can't waste in any more.（合并为一句）
Fresh water is______limited___ we can't waste it any more
7.Work harder,or you'll not succeed in you new job.（同义句）
______ ______work harder,you'll not stayed in your new job
8.Young people can learn a lot by keeping a net dog（对划线部分提问划线部分为by keeping a net dog） 最好讲下理由!谢谢