在城市市区范围内从事建筑工程施工,项目必须在工程开工( )日以前向工程所在地县级以上地方人民政府环境保护管理部门中报登记。
A.10
B.15
C.20
D.30
参考答案:B
—The duty of Project Hope is to help poor children, isn't it?
—Yes, it has built many schools________are for those children. [ ]
A. what
B. that
C. who
D. where
矩形硬母线的弯曲宜进行冷弯,如需热弯时,钢加热温度不应超()ºC。
A、250
B、350
C、500
D、600