1. The purpose of the modification bit in the Page Table is _________.
   1. To indicate whether the page is owned by a user process or a system process.
   2. To indicate whether the page needs to be written back to the virtual memory.
   3. To indicate whether the page is in the memory or not.
   4. To indicate whether the page has the write permission by the user process.
   5. Like a checksum to validate the integrity of the page
2. Based on the layered structure of Operating System, what is the OS layer of File Access Control?
   1. Hardware Layer
   2. Kernel Layer
   3. Service Layer
   4. Command Layer
   5. User Layer
3. The pointer in the storage allocation table is
   1. The address of the next allocated unit
   2. The physical address of the allocated unit
   3. The logical address of the allocated unit
   4. The size of allocated unit
   5. The checksum of allocated unit
4. What is the size of file allocation unit in Windows NTFS for file system up to 2.0 TB?
   1. 512 bytes
   2. 1024 bytes
   3. 2048 bytes
   4. 4096 bytes
   5. Variable size
5. Which of the following is a correct description of the storage allocation?
   1. Compared to memory allocation, the number of storage allocation units is much smaller.
   2. Compared to memory allocation, the frequency of change for storage allocation is much higher.
   3. The typical size of storage allocation unit is about 1MB.
   4. The size of storage allocation unit is set by the user application program.
   5. Once the storage allocation unit size is set, it is difficult to change.