Answer:polling and interrupt
Explanation: polling is a protocol in which the CPU constantly checked if a device request an important attention based on a request. The polling process unit constantly scans the device. Example of polling is when a parallel printer port is pulled to check whether it is ready for another character which involves examining as little as one bit of a byte.
interrupt is a mechanism whereby a device notifies a CPU that it requires a response based on a request. The CPU gets an interrupt signal via an interrupt request line allowing the CPU to spot it's current process and give priority to the interrupt request at that point in time. Example of interrupt is pressing a key on a keyboard which in turn triggers a specific interrupt handler.
The Bering Strait Land Bridge is a good example of this. During the Ice Age, humans from Asia migrated to what now is called North America in order to thrive in new lands, with new farming style.
The correct answers are:
(B) Poverty for most Russians
(C) Food shortages
(D) The writing of Karl Marx
