某无筋扩展基础底面处平均压力值为180kPa，采用毛石材料，其台阶允许宽高比为（）A

骨髓纤维化

按输出介质不同，供热锅沪可分为( )。

A．蒸汽锅炉

B．热水锅炉

C．导热油锅炉

D．燃气锅炉

— What courses are you going to take next term if you want to receive enough credits to get your degree?

— I don't know. But it's about time _____ on something. [ ]

A. I'd decide

B. I decided

C. I decide

D. I'm deciding

网络营销的特点是 （ ） 。

A．表现形式单一

B．营销成本提高

C．信息传递高效

D．时空受到限制

墙模板拼接时，U型卡应正反交替安装，间距不得大于（）。

A.100mm

B.200mm

C.300mm

D.400mm