Approximately how many tweets are posted on Twitter each day? 500 500 thousand 500 million 500 billion

Which of the following statements is incorrect in relation to processes: while, strictly speaking, at any instant of time, the cpu is running only one process, in the course of 1 second, it may work on several of them, giving the illusion of parallelism a process is just an instance of an executing program, including the current values of the program counter, registers, and variables processes can be created when an operating system is booted, created by the user, or a running process can create children processes there is a master process, which when started can last forever, and is not killable