砼中外加剂的掺量不超过水泥质量的（）
A.1%
B.2%
C.4%
D.5%
参考答案：D
---I called you yesterday afternoon, but there was no reply.
---I ______ a dolphin show the zoo with my cousins.
A．watched
B．will watch
C．am watching
D．was watching
在正常施工条件下，石砌体的砌筑高度宜为（）米。
A.1.1
B.1.2
C.1.3
D.1.4
E.1.5
