题干
When Li Lei was a small child, he hoped to be ______ policeman after he grew up and finally his dream came true.
A：a
B：a
C：the
D：不填
答案(点此获取答案解析）
A
A：a
B：a
C：the
D：不填
的所有棱长都相等，则二面角
的大小为（ ）