道德在调整人与人之间的关系实质上是调整（）
A.政治关系
B.经济关系
C.利益关系
D.社会关系
参考答案：C
等腰三角形的顶角是80°，则底角是多少度？
Do you think it is difficult ? [ ]
A. study English well
B. studies English well
C. studying English well
D. to study English well
