浅基础按基础刚度的不同可分为（）.
A.刚性基础
B.柔性基础
C.扩展基础
D.拓展基础
参考答案：A, C
We are required to________ our papers this afternoon. [ ]
A. hand out of
B. hand in
C. hand on
D. hand over
实行责任追究的原则是什么？
