钢结构具有良好的抗震性能是因为（）。
A.钢材的强度高
B.钢结构的质量轻
C.钢材良好的吸能能力和延性
D.钢结构的材质均匀
参考答案：C
赫尔巴特的四阶段教学过程是什么？
Several companies are _____ each other _____ a contract. [ ]
A. competing against; for
B. competed in; with
C. compete with; against
D. competing with; to
