建筑安装工程直接费系指______。A．施工准备、组织施工生产和管理所需费用 B．施

诊断呼吸衰竭的血气标准是（）。

A.PaO₂<8.6kPa（65mmHg）和（或）伴有PaCO₂>7.3kPa（55mmHg）

B.PaO₂<6.7kPa（50mmHg）和（或）伴有PaCO₂>8.0kPa（60mmHg）

C.PaO₂<8.0kPa（60mmHg）和（或）伴有PaCO₂>7.3kPa（55mmHg）

D.PaO₂<8.0kPa（60mmHg）和（或）伴有PaCO₂>6.7kPa（50mmHg）

E.PaO₂<8.6kPa（65mmHg）和（或）伴有PaCO₂>6.7kPa（50mmHg）

三糖铁培养基与双糖铁培养基的区别在于加与不加（）

A.乳糖

B.葡萄糖

C.蔗糖

D.枸橼酸铁

E.山梨醇

SQL语言集数据定义功能、数据操纵功能和数据控制功能于一体。如下所列语句中，是属于数据控制功能的语句______。

A．GRANT

B．CREATE

C．INSERT

D．SELECT

某化学兴趣小组从野外采集到石灰石样品24g，为测定其中碳酸钙的含量，他们将上述样品全部放入200g稀盐酸中，恰好完全反应，且石灰石中的杂质不与酸反应（化学方程式为：CaCO₃+2HCl=CaCl₂+H₂O

+CO₂↑），测得所得混合物质量为215.2g。试计算：

（1）根据__________定律，产生二氧化碳的质量为_____________g。

（2）石灰石中含碳酸钙的质量。

The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable (46) 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 (47) that it must meet. The starting point is usually a set of high-level requirements from the (48) that describe the project or problem.
In either case, the requirements definition team formulates an overall concept for the system and then defines (49) 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 (50) 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.

A．detailed

B．outlined

C．total

D．complete