this is( )ruler.写什么

this is( )ruler.写什么 --- --- ,Ben is this your ruler?yes,ie is 划线部分写什么? ( ) ruler is this? Is this red ruler ( this ruler is-----? is this your ruler this is his ruler This is "a ruler". This is .ruler..ruler is bule. This is a ruler.______ is black.应填什么 This is Alice._____ ruler is blue.应该填什么? This is my yellow ruler