Please answer the above three questions and explain explicitly

Suppose the following events occur on a single-core system with an xv6-like operating system in this order: process A outputs text to the screen after the write completes, process A asks the operating system to wait 4 seconds before running it again the operating system runs process B for 1 second the operating system received a keypress and notes it in a buffer the operating system continues running process B for another second the operating system runs process C for 2 seconds the operating system starts running process A again process A requests to read a key from the keyboard, and the read is processed using the buffer How many context switches occur during the scenario described above? How many system calls would process A make during the events described above? Besides the system calls made by process A, how many exceptions would occur during the events described above? Suppose the following events occur on a single-core system with an xv6-like operating system in this order: process A outputs text to the screen after the write completes, process A asks the operating system to wait 4 seconds before running it again the operating system runs process B for 1 second the operating system received a keypress and notes it in a buffer the operating system continues running process B for another second the operating system runs process C for 2 seconds the operating system starts running process A again process A requests to read a key from the keyboard, and the read is processed using the buffer How many context switches occur during the scenario described above? How many system calls would process A make during the events described above? Besides the system calls made by process A, how many exceptions would occur during the events described above