（29 ）下列叙述中，错误的是A ）宏能够一次完成多个操作 B ）可以将多个宏组成一个宏组C ）可以用变

某嵌入式系统采用字节编址方式，内存由A4000H～BBFFFH共有(35)KB，实现该内存区域需要32K×4bit的SRAM芯片共(36)片。

A．32

B．64

C．96

D．128

A．3

B．4

C．6

D．8

IEEE 1394具有(48)位地址空间，IEEE 1394的通信协议具有三个协议层，下面不属于这三个协议层的是(49)。

A．8

B．16

C．32

D．64

A．事务层

B．表示层

C．链路层

D．物理层

xactly, can be an open-ended question．(71)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(72)A diagram graphically represents things, and the relationships between these things. These(73)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．(74)are used to capture the physical organization of the things in your system, i.e., how one object relates to another．(75)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.

A．Programming

B．Analyzing

C．Designing

D．Modeling

A．views

B．diagrams

C．user views

D．structure pictures

A．things

B．pictures

C．languages

D．diagrams

A．Activity diagrams

B．Use-case diagrams

C．Structural diagrams

D．Behavioral diagrams

进程PA不断地向管道写数据，进程PB从管道中读数据并加工处理，如下图所示。如果采用PV操作来实现进程PA和进程PB间的管道通信，并且保证这两个进程并发执行的正确性，则至少需要(26)。

A．1个信号量，信号量的初值为0

B．2个信号量，信号量的初值分别为0、1

C．3个信号量，信号量的初值分别为0、0、1

D．4个信号量，信号量的初值分别为0、0、1、1

假设系统中有三类互斥资源R1、R2和R3，可用资源数分别为9、8和5。在T0时刻系统中有P1、P2、P3、P4和P5五个进程，这些进程对资源的最大需求量和已分配资源数如下表所示。如果进程按(27)序列执行，那么系统状态是安全的。

A．P1→P2→P4→P5→P3

B．P2→P1→P4→P5→P3

C．P2→P4→P5→P1→P3

D．P4→P2→P4→P1→P3