9- In an multi-threading OS, a critical section is where a- The system will fail if the code is executed b- the priority is the highest c- only one CPU can be running this code at one time d-the process runs the fastest 10- In an OS, two processes can a- Block Device Drivers b- The Network c- Inter-Process Communication d- The network 11- In each little man computer's mailbox are 3 digit numbers representing b- E-Mail c- Instruction and Data d- Data 12- Without hardware assistance, a computer with CPU, program counter and main memory can use this technique to allow different process to share the machine resource a- Time Sharing b- Preemptive Scheduleing c- Cooperative Scheduling d- Multi-Level Feedback Queue 13- The objective of multi-programming is to a- Have some process running at all times b- Have multiple programs waiting in a queue ready to run c- To minimize CPU utilization d- To maximize CPU utilization 14- The primary purpose of an operating system is a- To operate the system b-To make the most efficient use of the computer hardware c- To mak d- To make computer run faster e computers easier to use 15- The address of the next instruction to be executed by the current program is provided by the a- The Program Counter b- The Accumulator c- The MMU d- The Kernel 16- Multi-threading is for a- Many program running on many CPU b- Many program running on one CPU c- Single program running on one CPU d- SIngle program running on many CPU