This is a true statement. The dictionary definition of "synthesizer" is "an electronic musical instrument, typically operated by a keyboard, producing a wide variety of sounds by generating and combining signals of different frequencies."
Source B is more credible because it is from a government site, so it is meant to inform. It has a quote that shows drones are in debate.
At first look, the sources seem similar. They both were written around the same period and the URL appears almost identical. However, it is important to notice that source A is from a website ending in ".net," while source B ends in ".gov." Government websites are always more credible than a website ending in ".com" or ".net." Also, source A has advertisements, which means it is mostly for entertainment. In comparison, source B has a quote from President Obama. Since the research is about the invention of drones and their controversial uses, source B is also more helpful since the title specifically mentions the rules and misuse of drones.
<span>of prints determined by an artist to be printed from a single plate</span>
Answer:
length and breadth of the classroom
