在混凝土基础中加入粒径不超过()的毛石,且毛石体积不超过总体积的20%~30%,称为毛石混凝土基础。
A.200mm
B.300mm
C.400mm
D.500mm
参考答案:B
His grandfather _____ since two years ago. [ ]
A. died
B. has died
C. has dead
D. has been dead
在 Visual FoxPro 中,要运行菜单文件 menul.mpr,可以使用命令______。
A.DO menul
B.DO menul.mpr
C.DO MENU menul
D.RUN menul