List and explain four circumstances under which human being would be preferred to use of computer?

Computers are as yet devoid of sentience (or pretend to be). They also don't come standard with superior measures of diverse, cheap and efficient hardware. Some fields where this is a hindrance:
Image recognition - Takes complex algorithms (deep learning) and huge training sets, to achieve substandard results compared to people's built in functionality.
Environment - Whilst spacecraft and rovers can reach and roam freely places humans cannot, the sort of mundane situations encountered in everyday life of going from place to place, preparing food, washing up etc require even more effort.
Exception handling - Unless it is prematurely defined, a program cannot recognize nor react to unusual occurrences. "Ship happens".
Imagination - The source of innovation. It solves complex formulas, begets theories of the physics of the universe, finds solutions through invention to repetitive problems, makes people aspire for more than their basic needs.