Is this eraser yours?

Whose are these bags?

Whose shoes are these?

此外，shoes做主语时，若前面没有数量词的修饰,谓语动词需用复数形式,若前面有数量词,数量词的数目是一时,我们一般都用 this /a pair of shoes,谓语动词要用单数 如：This pair of shoes COSTS me a lot 。

这种题目主谓弄清楚就不难了，楼主好好学吧