Answer:
Cell phone - convenient communication
Industrial robot - reduction of human work-load
Power tool - faster construction
Explanation:
The cell phone one is obvious. Not so obvious is which of the remaining two goes with which. The industrial robot goes with less human work becasue industrial implies a factory, and robot means it is probably replacing humans. The remaining two also make sense together, because power tools do make construction much faster.
The answer is Genocide, genocide is the killing of a large group of people, especially those of a particular ethnic group or nation.
America declares war on Japan, and since Britain is America's ally it declares war as well
The correct answer is: The Central Powers