同一温度下，（）的辐射能力最大。A.黑体 B.镜体 C.灰体 D.透热体

The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable (6) of the technical requirements for the software product.

During the requirements definition phase, the requirements definition team uses an iterative process to expand a broad statement of the system requirements into a complete and detailed specification of each function that the software must perform and each (7) that it must meet. The starting point is usually a set of high-level requirements from the (8) that describe the project or problem.

In either case, the requirements definition team formulates an overall concept for the system and then defines (9) showing how the system will be operated, publishes the system and operations concept document, and conducts a system concept review (SCR).

Following the SCR, the team derives (10) requirements for the system from the high level requirements and the system and operations concept. Using structured or object-oriented analysis the team specifies the software functions and algorithms needed to, satisfy each detailed requirement.

10（）

A.detailed 

B.outlined 

C.total 

D.complete

命令按钮Command1的Caption属性为“退出(x)”，要将命令按钮的快捷键设为Alt+x，应修改Caption属性为______ 。 A) 在x前插入＆ 6)在x后插入＆ C) 在x前插入# D) 在x后插入#

铁路新线路的开辟与否往往必须在建路花费尽可能少的要求与新建路线的商业与贸易运输量尽可能多的要求之间取得妥协。这段话支持了这样一种观点，即新建铁路的线路( )。

A．决定了新兴贸易中心的位置

B．决定于起点与终点之间的距离是否最短

C．应该是一条造价最低的线路

D．不会总是建造成本最低的线路

关于设置固定支架或防晃支架的说法不正确的是（）

A.配水管宜在中点设一个防晃支架，当管径小于DN50时可不设

B.配水干管及配水管，配水支管的长度超过15m，每15m长度内应至少设2个防晃支架，当管径不大于DN40可不设

C.管径大于DN50的管道拐弯、三通及四通位置处应设1个防晃支架

D.防晃支架的强度，应满足管道、配件及管内水的重量再加50%的水平方向推力时不损坏或不产生永久变形

250km／h＞线路允许速度Vmax≥350km／h正线上，根据《高速铁路无砟轨道线路修理规则》规定，道岔静态几何尺寸容许偏差管理值中，水平的作业验收标准为（）mm。