Question 9 -- 76 Mach OS adopts 1 Layer structure 2 Modular structure 3 Microkernel structure 4 Hybrid structure Question 10 -- 16 In which mode does API run? 1 Only the user mode N Only the kernel mode 3 Both the kernel and user mode Question 11 -- /6 A A microkernel is a kernel 1 that is compressed before loading in order to reduce its resident memory size 2 that is stripped of all nonessential components 3 containing many components that are optimized to reduce resident memory size 4 that is compiled to produce the smallest size possible when stored to disk Question 12 -- 76 Microkernels use for communication 1 shared memory 2 system calls 3 message passing 4 virtualization