4.—Are those your books?(同上）—No,( they )( aren't ).
5.Is that your tuler?(改为复数句）（ Are ）（ those ）your ( rulers )?
6.Are these her erasers?(改为单数句）（Is ）（this）her( eraser )?



希望能帮到你,祝更上一层楼O(∩_∩)O
有不明白的请继续追问(*^__^*)