题干
— Do you think yesterday's math problem was difficult?
— Yes. I could work it out.
A：hardly
B：easily
C：finally
D：nearly
答案(点此获取答案解析）
A
x+1的图像与x轴、y轴分别交于点A、B，把Rt△AOB绕点A顺时针旋转角α（30°＜α＜180°），得到△AO′B′． 
