— Is this _____ ruler?

This is Alice._____ ruler is blue.应该填什么? This is a ruler._____ ruler is blue中____应填写The,还是A? This ruler is long.转化为The ruler____ _____. ( ) 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. _____ a ruler ? yes,____. A.Is this, it is B.Is that,it‘s C. this ruler is mine ._____ is over there.A:she B:she's C:her