断路器的分闸时间又称固分时间。

在○里填“>”“<”或“=”。

27÷3×7○62                                   28+125×8○1028 

88-37×2○90÷15×9                       250+50×5○35×5×3 

74○320-36×7                                  101○18+11×8

（16分）如图所示，一根内壁光滑的直角三角形玻璃管子处于竖直平面内，倾斜角为θ= 37°，让两个小球分别从顶点A由静止开始出发，一个球沿AC滑下，到达C所用的时间为t₁，另一个球竖直自由下落经过B到达C，所用的时间为t₂，在转弯处有个极小的光滑圆弧，可确保小球转弯时无机械能损失，且转弯时间可以忽略不计。问：

（1）计算t₁∶ t₂的值；

（2）若用同样的玻璃管把ABC轨道改为如图所示的ADEFC（在转弯处均有个极小的光滑圆弧），仍让小球从A静止开始运动，依次通过D、E、F后到达C点所用时间为t₃，试定性说明t₃和t₁、t₂的大小关系。

关于麻痹性肠梗阻的临床表现，下列哪项是错误的()

A．肠鸣音高亢，伴气过水音

B．常无阵发性绞痛

C．腹胀往往显著

D．腹痛为持续性钝痛

E．X线检查显示大、小肠全部充气扩张

The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable (1) 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 (2) that it must meet. The starting point is usually a set of high-level requirements from the (3) that describe the project or problem.

In either case, the requirements definition team formulates an overall concept for the system and the defines (4) 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 (5) 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.

4（）

A．rules

B．principles

C．scenarios

D．scenes

全新别克GL8豪华商务车拥有先进的安全保障体系，其前后防撞钢梁的厚度分别达到（）。

A.5mm/5mm

B.1mm/5mm

C.3mm/5mm

D.5mm/3mm