1.All the pictures in the room are for sale. (for sale划横线)
= All the pictures in the room are to be sold.
2.You must finish your work by Friday at the latest. (by Friday at the latest划横线)
= When is deadline for you to finish your work?
= When is deadline of you/your finishing your work?
3.There is going to be a sports meeting next week in our school.
= There will be a sports meeting next week in our school.
= A sports meeting is going to be held next week in our school.
= A sports meeting will be held next week in our school.
参考资料:原创回答团(第159号会员)