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问题 选择题

如图所示，匀强磁场的磁感应强度为0.4T，通电直导线与磁场方向垂直，导线长度为0.5m，导线中电流为2A．该导线所受安培力的大小是（　　）

A．0.1 N

B．0.2 N

C．0.3 N

D．0.4 N

答案

导线与磁场垂直，导线受到的安培力F=BIL=0.4×2×0.5=0.4N；

故选D．

单项选择题

It should go without saying that the focus of UML is modeling. However, what that means, exactly, can be an open-ended question. （） is a means to capture ideas, relationships, decisions, and requirements in a well-defined notation that can be applied to many different domains. Modeling not only means different things to different people, but also it can use different pieces of UML depending on what you are trying to convey. In general, a UML model is made up of one or more （） . A diagram graphically represents things, and the relationships between these things.These （） can be representations of real-world objects, pure software constructs, or a description of the behavior of some other objects. It is common for an individual thing to show up on multiple diagrams; each diagram represents a particular interest,or view, of the thing being modeled.UML 2.0 divides diagrams into two categories: structural diagrams and behavioral diagrams. （） are used to capture the physical organization of the things in your system, i. e. , how one object relates to another. （） focus on the behavior of elements in a system. For example, you can use behavioral diagrams to capture requirements, operations, and internal state changes for elements.

In general, a UML model is made up of one or more （）.

A．views

B．diagrams

C．user views

D．structure pictures
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多项选择题

路基的基本要求有( )。

A．应具有足够的稳定性

B．防滑且耐磨

C．透水性好

D．水温稳定性

E．具有足够的强度
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