The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable (87) 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 (88) that it must meet. The starting point is usually a set of high-level requirements from the (89) that describe the project or problem.
In either case, the requirements definition team formulates an overall concept for the system and the defines (90) showing how the system will be operated, publishes the system and operation concept documents, and conducts a system concept review (SCR).
Following the SCR, the team derives (91) requirements for the system from the highlevel requirements and the system operations concept. Using structured or object-oriented analysis,the team specifies the software functions and algorithms needed to satisfy each detailed requirements.

A. criterion B. standard
C. model D. system

在碳化塔的运行过程中，若发现碳化尾气CO₂含量高则下列选项中不应出现的操作是（）。

A、减少进气量或加快取出速度

B、加大中和水量或减慢取出速度

C、减少中段气进气量

D、提高氨盐水和中和水的温度