水泥粉煤灰碎石桩,在桩顶和基础之间应设置褥垫层,褥垫层厚度宜取( )。
A.50~150mm
B.150~300mm
C.300~450mm
D.200~400mm
参考答案:B
Mobile computers-which (71) laptops, notebooks, subnotebooks and handhelds- (72) so ubiquitous in such a short time, no surprise to hear who say: "It will define the leading edge (73) the next five years or so." The most remarkable (74) mobile computers is the amount of data storage and memory packed (75) their tiny boxes. These devices not only handle windows easily but also run storage-hungry programs.
A.from
B.for
C.about
D.at
E.on
F.into
信息系统实施的主要工作包括()
A.程序设计
B.计算机系统方案的选择
C.系统总体结构的确定
D.软件系统模块的划分