题干
What's this?
A：It's a chick.
B：It's a duck.
答案(点此获取答案解析）
A
What's this?
A：It's a chick.
B：It's a duck.
3°，为了看清楚些，用一放大倍数为5倍的放大镜观察，可以看到这个角的度数为： 