Answer:
a. global warming
Explanation:
that's the definitain of global warming
The synthesizer, the Theremin, and the electronic organ are totally electronic
instruments. They don't make any sound at all without electronic circuits and
electric power.
The acoustic guitar is not inherently an electronic instrument. It can be made
louder with microphones, and given special effects with other electronic stuff.
Whether any of this is actually an 'enhancement' is open to debate.
Without the ability to measure, it would be difficult for scientists to conduct experiments or form theories. Not only is measurement important in science and the chemical industry, it is also essential in farming, engineering, construction, manufacturing, commerce, and numerous other occupations and activities.