一、单项选择。(15分)
( )21. It isn’t ______ ring. It’s ________ eraser.
A. an, an B. a, an C. an, a D. a, a
( )22. -What’s this in English ? - ______ a map.
A. It’s B. That’s C. This is D. It
( )23.-What color is it? -________________.
( )21. It isn’t ______ ring. It’s ________ eraser.
A. an, an B. a, an C. an, a D. a, a
( )22. -What’s this in English ? - ______ a map.
A. It’s B. That’s C. This is D. It
( )23.-What color is it? -________________.