Quite well in the important exam , he came back home,    and smiling.

A．Having done; relaxed

B．having done ; relaxing

C．having been done ; relaxing

D．Done; relaxed

砌筑砂浆试块强度等级必须满足同一验收批砂浆试块抗压强度平均值必须大于或等于设计强度等级的（）倍。

A.0.9

B.1.0

C.1.1

D.1.2