This is ID card and that is eraser.A. a aB. an anC. a anD. an a

问题补充：

This is ID card and that is eraser.

A. a,a

B. an,an

C. a,an

D. an,a

答案：

A. a,a

(答案→)B. an,an

C. a,an

D. an,a

解析：在名词前元音音素用an，辅音音素用a，本题两个空都是元音音素，故选B。