The best answer to this question is D. a god scientific question should be based on observations instead of just imagination.
Hope this helps.
Convection currents are formed due to the density difference between layers of fluid. The heated layers rise up because their density is less than that of the colder layers. Hope this helps!
100% C . By size and distance
B. By vibrations in wires or strings
To calculate instantaneous speed, we need to divide part of the total distance traveled by time. However, we don't want to use the distance of the entire trip, because that will give us average speed.
