Answer:
An echo is formed as a result of reflection of the original sound which returns to the listener. You might have experienced Echo in an EMPTY ROOM but no echo is produced after the room is occupied. To avoid echo from being produced the echo has to be absorbed.
Explanation:
A well maintained bicycle is key. Oil the chain so that it's less likely to get hung up. It will have a smoother flow. Another could be in their clothing. Notice they usually wear good fitting clothing? I believe the more from fitting pants help clothing friction. Another way could be keeping the tires well inflated so that the tires aren't dragging. Rolling along smoothly on properly inflated tires seems like a must. Get a few more answers along with mine, so that you have a variety to choose from.
C. because you need voltage in a circuit to cause current.
Answer: The correct answer is C.
2/10 is simplified to 1/5, that is the factor that changes.
Figure B. The second option.