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问题 问答题

如图甲所示，敲击鼓面会听到鼓声，若向鼓面上撒些纸屑或泡沫塑料的颗粒，还会看到它们在鼓面上跳动．如图乙所示，敲击音叉会听到声音，若将发声的音叉靠近一只悬挂着的轻质小球，小球会摆动．这些现象说明______．其实不光是这些现象，大量的实验观察表明：一切______物体都在振动．

答案

敲击鼓面会听到鼓声，若向鼓面上撒些纸屑或泡沫塑料的颗粒，还会看到它们在鼓面上跳动；用竖直悬挂的泡沫塑料球接触发声的音叉时，泡沫塑料球被弹起，把音叉微小的振动放大，便于观察；这些现象说明发声的物体在振动；大量的实验观察表明：一切发声的物体都在振动．

故答案为：发声的物体在振动；发声．

配伍题 B型题

可调整结肠动力、刺激结肠黏膜细胞的增生（）。
是小肠黏膜和胰腺细胞的主要能源物质（）。
是巨噬细胞的主要能源物质（）。

A.谷氨酰胺

B.膳食纤维

C.生长激素

D.支链氨基酸

E.精氨酸
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单项选择题 共用题干题

Feasibility should be measured throughout the life cycle of system development. The scope and complexity of an apparently feasible project can change after the initial problems and opportunities are fully analyzed or after the system has been designed. Thus, a project that is feasible at one point may become infeasible later. The first feasibility analysis is conducted during the (1). The (2) represents a major feasibility analysis activity since it charts one of many possible implementations as the target for systems design. (3)  is a measure of how well the solution will work in the organization. It is also a measure of how people feel about the system. When it is determined in the later stages of the system life cycle, (4)  is often performed with a working prototype of the proposed system. This is a test of the system's user interfaces and is measured in how easy they are to learn and to use and how they support the desired productivity levels of the users. Economic feasibility has been defined as a cost-benefit analysis. The (5)  technique is a simple and popular method for determining if and when an investment will pay for itself.

空白（5）处应选择（）

A.payback analysis

B.return-on-investment analysis

C.present value

D.time value of money
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