本次澳洲代写是一个关于操作系统的线上测试
1. An operating system is a group of()
1. Interrupt handlers
2. Resource management programs
3. Equipment management programs
4. File management programs
2.The operating system that allows multiple users to interact with each other is ()
1. Batch processing system
2. Real time system
3. Distributed processing system
4. Time sharing system
3. An operating system provides ( ) for users to store and access their data conveniently.
1. File system
2. CPU scheduler
3. Interrupt handlers
4. Paging system
4.Of the following operations, () is executed in user mode
1. Process scheduler
2. Page-fault handler
3. Clock interrupt handler
4. Command interpreter
5.One essential difference between a process and a program is ().
1. a process is stored in memory, and a program is stored in external memory
2. a process is contained in a single file, and a program spans in multiple files
3. a process is active, and a program is passive
4. a process uses resources of a computer system, and a program does not use resources
6.Conceptually, an OS manages computer system resources by performing the following allocate 3 tasks ()
1. monitor the usage of resources, allocate resources, deallocate resources
2. allocate CPU to processes, allocate memory to processes, manage file systems
3. compile, debug, execute resource management programs
4. merge, split and allocate resources
7.If there are five plotters(device name) in the system, and more than one process need to use two plotters. If each process is allowed to apply for only one at a time, at most () processes are allowed to participate in the competition without deadlock.
1. 5
2. 3
3. 2
4. 4
8.If process performs signal operation on semaphore s with initial value 0, then the value of semaphore s after signal operation should be ()
1. -2
2. +1
3. 0
4. -1
9.For a process currently in a printing queue, when the printing is finished, the status of the process will be changed ()
1. From ready to run
2. From run to ready
3. From run to waiting
4. From waiting to ready
10.When the allocated time slice of a process is used up, the process is put to ().
1. Waiting queue
2. Ready queue
3. Running queue
4. Arbitrary queue
11.Round-robin CPU allocation is used to schedule the process for the purpose ()
1. The shortest CPU process is required to do first
2. All processes can get the system response in time
3. First come first service
4. Processes with higher priority get response more quickly
12.A process needs to read data from the disk during its execution. At this time, the status of the process will be changed ().
1. From running to ready
2. From waiting to ready
3. From running to waiting
4. From ready to run
13.The existence of fragmentation makes memory space utilization ().
1. Improved
2. Reduced
3. Have no effect
4. Increased
14.In the partitioned management, best-fit allocation allocates () to a process.
1. a randomly chosen hole
2. the first hole that fits the process
3. the largest hole
4. the smallest hole that fits the process
15.Data stored in an external storage is the data that ()
1. must be loaded into memory before access
2. is not needed during process execution
3. is the information in the high speed buffer
4. can be directly accessed by CPU
16.If the files of different users can have the same file name, usually () is used to ensure the security of access by name.
1. a multi-level hierarchical directory
2. an index table
3. a set of pointers
4. a linear table
17.The information stored in a two-level directory structure is ().
1. directory structure and all files
2. only the directory structure of all files
3. data stored in all files
4. file names of all files
18.In an operating system, users usually use () when accessing I/O devices
1. device brand name
2. physical device name
3. logical device name
4. virtual device name
19.After a user program sends out a disk I/O request, the correct processing flow in the system is ()
1. user program → system call → interrupt handler → device driver
2. user program → device driver → system call → interrupt handler
3. user program → system call → device driver → interrupt handler
4. user program → device driver → interrupt handler → system call
20.The open, close, read and write operations to I/O devices are completed by ()
1. user program
2. compiler
3. device drivers
4. device allocator