When our teacher comes into the room we greet him with “Good morning.”A. aB. theC. anD.

问题补充：

When our teacher comes into the room, we greet him with “Good morning.”

A. a

B. the

C. an

D. one

答案：

(答案→)A. a

B. the

C. an

D. one

解析：Good为发辅音字母开头的单词。