低温冷藏的温度应控制在（）。A.-4℃ B.0℃以下 C.0～5℃以下 D.2℃～1

项目经理必须在符合预算与超过预算为避免破坏环境处理窝巢之间做出选择，只有项目经理知道这个问题，项目经理应该怎么做？（）

A、将窝巢从项目区中搬出

B、不顾窝巢，完成项目

C、提出一项变更请求

D、除去窝巢，减少额外费用

换向极的作用是改善（）的换向性能，消除或削弱电刷下的火花。

A、交流电机

B、直流电机

C、高压电机

D、低压电机

The purpose of the requirements definition phase is to produce a clear, complete，consistent, and testable______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______that it must meet. The starting point is usually a set of high-level requirements from the______that describe the project or problem.
In either case, the requirements definition team formulates an overall concept for the system and then defines______showing how the system win be operated, publishes the system and operations concept document, and conducts asystem concept review(SCR).
Following the SCR，the team derives______requirements for the system from the operations concept. Using structured or object-oriented analysis, the team specifies the software functions and algorithms needed to satisfy each detailedrequirement.

A．rules
B．principles
C．scenarios
D．scenes

男性，48岁。1年前开始逐渐出现颈后酸痛不适，双手麻木，不灵活，使用筷子困难。行走时有踩棉花感，易跌倒。查体：前臂外侧痛觉减退，四肢肌张力增高，双Hoffmann试验（+），踝阵挛（+），Babinski征（+）。辅助检查：X线检查见颈5～6生理曲度消失，局部轻度后凸畸形，间隙狭窄，增生硬化，椎管矢状径15mm。

进一步检查首选（）

A.颈椎CT

B.颈椎MRI

C.脊髓造影

D.诱发电位

E.上肢肌电图

月计划在（）报批。

A.上月二十五日前

B.上月二十日前

C.上月二十八日前

D.上月二十一日前