相关题目
171、As we all know, databases were originally constructed as a means of consolidating or centralizing information.The more modem perspective, however, is to view databases as a means of integrating information that may be stored on different machines throughout a network or an internet.For instance, an international corporation may be stored and maintain local employee records at local sites yet link these records via a network to create a distributed database——a single large integrated database that consists of data residing on different machines.A distributed database may contain fragmented and/or replicated data.The first case is exemplified by the previous employee-records example in which different fragments of the database are stored in different locations.In the second case, duplicates of the same database component are stored at different locations.Such replication may occur as a means of reducing information retrieval time.Both cases pose problems not present in more traditional centralized systems - such as how to disguise the distributed nature of the database so that it functions as a coherent system or how to ensure that replicated portions of a database remain duplicates of each other as updates occur.In turn, the study of distributed databases is a current area of research.(5)、What is the passage mainly about?
171、As we all know, databases were originally constructed as a means of consolidating or centralizing information.The more modem perspective, however, is to view databases as a means of integrating information that may be stored on different machines throughout a network or an internet.For instance, an international corporation may be stored and maintain local employee records at local sites yet link these records via a network to create a distributed database——a single large integrated database that consists of data residing on different machines.A distributed database may contain fragmented and/or replicated data.The first case is exemplified by the previous employee-records example in which different fragments of the database are stored in different locations.In the second case, duplicates of the same database component are stored at different locations.Such replication may occur as a means of reducing information retrieval time.Both cases pose problems not present in more traditional centralized systems - such as how to disguise the distributed nature of the database so that it functions as a coherent system or how to ensure that replicated portions of a database remain duplicates of each other as updates occur.In turn, the study of distributed databases is a current area of research.(4)、 According to the passage, why we need to use distributed database in some conditions?
171、As we all know, databases were originally constructed as a means of consolidating or centralizing information.The more modem perspective, however, is to view databases as a means of integrating information that may be stored on different machines throughout a network or an internet.For instance, an international corporation may be stored and maintain local employee records at local sites yet link these records via a network to create a distributed database——a single large integrated database that consists of data residing on different machines.A distributed database may contain fragmented and/or replicated data.The first case is exemplified by the previous employee-records example in which different fragments of the database are stored in different locations.In the second case, duplicates of the same database component are stored at different locations.Such replication may occur as a means of reducing information retrieval time.Both cases pose problems not present in more traditional centralized systems - such as how to disguise the distributed nature of the database so that it functions as a coherent system or how to ensure that replicated portions of a database remain duplicates of each other as updates occur.In turn, the study of distributed databases is a current area of research.(3)、Which of the following statements is true?
171、As we all know, databases were originally constructed as a means of consolidating or centralizing information.The more modem perspective, however, is to view databases as a means of integrating information that may be stored on different machines throughout a network or an internet.For instance, an international corporation may be stored and maintain local employee records at local sites yet link these records via a network to create a distributed database——a single large integrated database that consists of data residing on different machines.A distributed database may contain fragmented and/or replicated data.The first case is exemplified by the previous employee-records example in which different fragments of the database are stored in different locations.In the second case, duplicates of the same database component are stored at different locations.Such replication may occur as a means of reducing information retrieval time.Both cases pose problems not present in more traditional centralized systems - such as how to disguise the distributed nature of the database so that it functions as a coherent system or how to ensure that replicated portions of a database remain duplicates of each other as updates occur.In turn, the study of distributed databases is a current area of research.(2)、 When you want to reduce information retrieval time in a distributed database, which following method may work?
171、As we all know, databases were originally constructed as a means of consolidating or centralizing information.The more modem perspective, however, is to view databases as a means of integrating information that may be stored on different machines throughout a network or an internet.For instance, an international corporation may be stored and maintain local employee records at local sites yet link these records via a network to create a distributed database——a single large integrated database that consists of data residing on different machines.A distributed database may contain fragmented and/or replicated data.The first case is exemplified by the previous employee-records example in which different fragments of the database are stored in different locations.In the second case, duplicates of the same database component are stored at different locations.Such replication may occur as a means of reducing information retrieval time.Both cases pose problems not present in more traditional centralized systems - such as how to disguise the distributed nature of the database so that it functions as a coherent system or how to ensure that replicated portions of a database remain duplicates of each other as updates occur.In turn, the study of distributed databases is a current area of research.(1)、Which of the following descriptions is the modern perspective of database?
170、The principal function of main memory is to act as an intermediary between the central processing unit ( ) and the rest of the computer system components.It functions as a sort of desktop on which you place the things with which you are about to begin to work.The CPU can utilize only those software instructions and data that are stored in main memory.As you know, main memory is random access memory, or RAM.The name derives from the fact that data can be stored in and retrieved at random from anywhere in the electronic main memory, chips in approximately the same amount of time, no matter where the data is.Main memory is in an electronic, or volatile state.When the computer is off, main memory is empty; when it is on, main memory is capable of receiving and holding a copy of the software instructions and data necessary processing.Because main memory is a volatile form of storage that depends on electric power and the power can go off during processing, users often save their work frequently onto nonvolatile secondary storage devices such as diskettes or hard disks.In general, main memory is used for the following purposes: A copy of the main software program stored in the computer that controls the general operation of the computer.This copy is loaded into main memory when the computer is turned on, and it stays there as long as the computer is on.(1) Temporary storage of a copy of application program instructions ( ) to be retrieved by the CPU for interpretation and execution.(2) Temporary storage of data that has been input from the keyboard or other input device until instructions call for the data to be transferred into the CPU for processing.(3) Temporary storage of data that has been produced as a result of processing until instructions call for the data to be used again in subsequent processing or to be transferred to an output device such as the screen, a printer, or a disk storage device.(5)、When you want to save data for a long time, which following component can be used?
170、The principal function of main memory is to act as an intermediary between the central processing unit ( ) and the rest of the computer system components.It functions as a sort of desktop on which you place the things with which you are about to begin to work.The CPU can utilize only those software instructions and data that are stored in main memory.As you know, main memory is random access memory, or RAM.The name derives from the fact that data can be stored in and retrieved at random from anywhere in the electronic main memory, chips in approximately the same amount of time, no matter where the data is.Main memory is in an electronic, or volatile state.When the computer is off, main memory is empty; when it is on, main memory is capable of receiving and holding a copy of the software instructions and data necessary processing.Because main memory is a volatile form of storage that depends on electric power and the power can go off during processing, users often save their work frequently onto nonvolatile secondary storage devices such as diskettes or hard disks.In general, main memory is used for the following purposes: A copy of the main software program stored in the computer that controls the general operation of the computer.This copy is loaded into main memory when the computer is turned on, and it stays there as long as the computer is on.(1) Temporary storage of a copy of application program instructions ( ) to be retrieved by the CPU for interpretation and execution.(2) Temporary storage of data that has been input from the keyboard or other input device until instructions call for the data to be transferred into the CPU for processing.(3) Temporary storage of data that has been produced as a result of processing until instructions call for the data to be used again in subsequent processing or to be transferred to an output device such as the screen, a printer, or a disk storage device.(4)、 Main memory is also called?
170、The principal function of main memory is to act as an intermediary between the central processing unit ( ) and the rest of the computer system components.It functions as a sort of desktop on which you place the things with which you are about to begin to work.The CPU can utilize only those software instructions and data that are stored in main memory.As you know, main memory is random access memory, or RAM.The name derives from the fact that data can be stored in and retrieved at random from anywhere in the electronic main memory, chips in approximately the same amount of time, no matter where the data is.Main memory is in an electronic, or volatile state.When the computer is off, main memory is empty; when it is on, main memory is capable of receiving and holding a copy of the software instructions and data necessary processing.Because main memory is a volatile form of storage that depends on electric power and the power can go off during processing, users often save their work frequently onto nonvolatile secondary storage devices such as diskettes or hard disks.In general, main memory is used for the following purposes: A copy of the main software program stored in the computer that controls the general operation of the computer.This copy is loaded into main memory when the computer is turned on, and it stays there as long as the computer is on.(1) Temporary storage of a copy of application program instructions ( ) to be retrieved by the CPU for interpretation and execution.(2) Temporary storage of data that has been input from the keyboard or other input device until instructions call for the data to be transferred into the CPU for processing.(3) Temporary storage of data that has been produced as a result of processing until instructions call for the data to be used again in subsequent processing or to be transferred to an output device such as the screen, a printer, or a disk storage device.(3)、What kind of data can be utilized by CPU?
170、The principal function of main memory is to act as an intermediary between the central processing unit ( ) and the rest of the computer system components.It functions as a sort of desktop on which you place the things with which you are about to begin to work.The CPU can utilize only those software instructions and data that are stored in main memory.As you know, main memory is random access memory, or RAM.The name derives from the fact that data can be stored in and retrieved at random from anywhere in the electronic main memory, chips in approximately the same amount of time, no matter where the data is.Main memory is in an electronic, or volatile state.When the computer is off, main memory is empty; when it is on, main memory is capable of receiving and holding a copy of the software instructions and data necessary processing.Because main memory is a volatile form of storage that depends on electric power and the power can go off during processing, users often save their work frequently onto nonvolatile secondary storage devices such as diskettes or hard disks.In general, main memory is used for the following purposes: A copy of the main software program stored in the computer that controls the general operation of the computer.This copy is loaded into main memory when the computer is turned on, and it stays there as long as the computer is on.(1) Temporary storage of a copy of application program instructions ( ) to be retrieved by the CPU for interpretation and execution.(2) Temporary storage of data that has been input from the keyboard or other input device until instructions call for the data to be transferred into the CPU for processing.(3) Temporary storage of data that has been produced as a result of processing until instructions call for the data to be used again in subsequent processing or to be transferred to an output device such as the screen, a printer, or a disk storage device.(2)、 According to the passage, which of the following statements is true?
170、The principal function of main memory is to act as an intermediary between the central processing unit ( ) and the rest of the computer system components.It functions as a sort of desktop on which you place the things with which you are about to begin to work.The CPU can utilize only those software instructions and data that are stored in main memory.As you know, main memory is random access memory, or RAM.The name derives from the fact that data can be stored in and retrieved at random from anywhere in the electronic main memory, chips in approximately the same amount of time, no matter where the data is.Main memory is in an electronic, or volatile state.When the computer is off, main memory is empty; when it is on, main memory is capable of receiving and holding a copy of the software instructions and data necessary processing.Because main memory is a volatile form of storage that depends on electric power and the power can go off during processing, users often save their work frequently onto nonvolatile secondary storage devices such as diskettes or hard disks.In general, main memory is used for the following purposes: A copy of the main software program stored in the computer that controls the general operation of the computer.This copy is loaded into main memory when the computer is turned on, and it stays there as long as the computer is on.(1) Temporary storage of a copy of application program instructions ( ) to be retrieved by the CPU for interpretation and execution.(2) Temporary storage of data that has been input from the keyboard or other input device until instructions call for the data to be transferred into the CPU for processing.(3) Temporary storage of data that has been produced as a result of processing until instructions call for the data to be used again in subsequent processing or to be transferred to an output device such as the screen, a printer, or a disk storage device.(1)、1.What is the passage mainly about?
