假定每一车次具有惟一的始发站和终点站。如果实体“列车时刻表”属性为车次、始发站、发车时间、终点站、到达时间，该实体的主键是(42)；如果实体“列车运行表”属性为车次、日期、发车时间、到达时间，该实体的主键是(43)。通常情况下，上述“列车时刻表”和“列车运行表”两实体型间(44)联系。
以太网100BASE-TX标准规定的传输介质是(61)。
事务的ACID性质中，关于原子性(atomicity)的描述正确的是(52)。
以下不属于中间件技术的是(65)。
在分布式数据库的垂直分片中，为保证全局数据的可重构和最小冗余，分片满足的必要条件是(53)。
Networks can be interconnected by different devices. In the physical layer, networks can be connected by(66)or hubs, which just move the bits from one network to an identical network. One layer up we find bridges and switches, which operate at data link layer. They can accept(67), examine the MAC address, and forward the frames to a different network while doing minor protocol translation in the process. In the network layer, we have routers that can connect two networks. If two networks have(68)network layer, the router may be able to translate between the packet formats. In the transport layer we fmd transport gateway, which can interface between two transport connections. Finally, in the application layer, application gateways translate message(69). As an example, gateways between Internet e-mail and X.400 e-mail must(70)the e-mail message and change various header fields.
容量为64块的Cache采用组相联方式映像，字块大小为128个字，每4块为一组。若主存容量为4096块，且以字编址，那么主存地址应为(7)位，主存区号应为(8)位。
关于事务的故障与恢复，下列描述正确的是(54)。
The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable(71 )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 sofrware must perform. and each(72)that it must meet. The starting point is usually a set of high-level requirements from the(73)that describe the project or problem.In either case, the requirements definition team formulates an overall concept for the system and then defines(74)showing how the system will be operated, publishes the system and operations concept document, and conducts a system concept review(SCR).Following the SCR, the team derives(75)requirements for the system from the high level requirements and the system and operations concept. Using structured or object-oriented analysis, the team specifies the software functions and algorithms needed to satisfy each detailed requirement.
不能激活触发器执行的操作是(55)。
某一非确定性有限自动机(NFA)的状态转换图如下图所示，与该NFA等价的正规式是(28)，与该NFA等价的DFA是(29)。