Answer:
The answer is a," their receptors are sensitive to chemical molecules."
The answer is D, or Outer Space.
Explanation:
Sound is implemented through mechanical wave transferral, which requires a medium (solid, liquid, or gas) to travel through. Because sound is a mechanical wave, it cannot travel through vacuums (space).
One simple use of the elements of the electromagnetic spectrum that we use during our everyday lives is our daily use of microwave radiation. microwave radiation is absorbed by water molecules which heats up and cooks the food whilst killing bacteria. Another would be ultraviolet radiation which we use daily in things such as light bulbs. The sun also uses this. Lastly, we use radio waves constantly. May it be tv programs, radio, or our cell phones.
Answer:
Part 1: 0.3789
Part 2: 746 J
Part 3: 2.162 kW
Explanation:
Part 1:
Eff= 
Eff= 0.378873 ≈ 0/3789
Part 2:
W= 0.3789(1969)
W= 746 J
Part 3:

Power= 2162.3188 Watts
2162.3188 W-----> 2.162 kW