题干
— Can you help me make lanterns?
— .
A：Yes, I am.
B：No, I can.
C：Yes, I do.
D：Sorry, I can't.
答案(点此获取答案解析）
D
— Can you help me make lanterns?
— .
A：Yes, I am.
B：No, I can.
C：Yes, I do.
D：Sorry, I can't.
点C在∠AOB内，且∠AOC=45°，设
等于 （ ）