土围堰施工中，内坡脚与基坑的距离根据河床土质及基坑开挖深度而定，但不得小于（）。
A．1m
B．2m
C．3m
D．4m
参考答案：A
,Mother will wait for him to have dinner together.
A．However late is he
B．However he is late
C．However is he late
D．However late he is
在完全竞争市场中，行业的长期供给曲线取决于( )。
A．SAC曲线最低点的轨迹
B．SMC曲线最低点的轨迹
C．LAC曲线最低点的轨迹
D．LMC曲线最低点的轨迹
