问题 问答题 简答题

鱼类为什么离开水后即死亡?

答案

参考答案:

鱼类离开水后,原来依靠水的浮力完全张开的鳃丝和鳃小片彼此黏连,呼吸面大大减少,无法获取充足的氧气,且鳃丝暴露在空气中,因水分蒸发而引起鳃片干燥,破坏了鳃的结构,使之失去呼吸机能而死亡。

单项选择题

Information systems design is defined as those tasks that focus on the specification of a detailed computer-based solution. Typically, there are four systems design tasks for in-house development.

1) The first task is to specify (71) ,which defines the technologies to be used by one, more, or all information systems in terms of their data, processes, interfaces, and network components. This task is accomplished by analyzing the data models and process models that are initially created during requirements analys16.

2) The next systems design task is to develop the (72) . The purpose of this task is to prepare technical design specifications for a database that will be adaptable to future requirements and expansion.

3) Once the database prototype has been built, the systems designer can work closely with system users to develop input, output and dialogue specifications. The (73) must be specified to ensure that the outputs are not lost, misrouted, misused, or incomplete.

4) The fourth design task involves packaging all the specifications from the previous design tasks into a set of specifications that will guide the (74) activities during the following phases of the systems development methodology.

Finally, we should (75) and update the project plan accordingly. The key deliverable should include a detailed plan for the construction phase that should follow.

(71)处应填()。

A.an application architecture

B.a distributed system

C.a system scope

D.a system physical model

多项选择题