This is a ruler(对a ruler提问) ----- -----this?

This is a ruler(对a ruler提问) ----- -----this? this is a yellow ruler.（对划线部分提问）a yellow ruler。是划线部分 That's a ruler.对 a ruler 提问.Is this an apple?改为复数句子. This is a ruler.(对画线部分提问) a ruler 下面有线! This is a red ruler对划线部分提问划线部分：a red ruler This is a green ruler 对a green ruler 提问.怎么提? This is a ruler and That a ruler ,too和That is aruler and This is a ruler,too那个对,为什么 This is a red ruler 用a red ruler 提问 This is a red apple.该成疑问句 lt‘s a ruler in English .对a ruler提问 This is a ruler 改为一般疑问句 This is a ruler改为一般疑问句 Is this a ruler.(做否定回答) is,a,this,red,ruler 连成句 this is a ruler 改为复数 this ruler is-----?a:myb:mine this is a ruler.改复数 翻译：and this is a ruler This is a ruler【对划线部分提问[a ruler]】 —— —— —— ——?