Answer: The hierarchical formation model suggests that galaxies may have been formed by subsequent mergers of smaller galaxies and that today each galaxy houses at least a supermassive black hole.
Explanation: During a fusion of galaxies, the stars that composes it suffer the tidal force, intensifying your action as the galaxies approaching. When two galaxies merges themselves, the astronomers believes that they loss a huge part of their mass, forming the supremassive black hole, that stays in the middle of the galaxie.
The supermassive black holes are originated from the evolution of high mass stars. They were formed by huge clouds of gas or clusters of millions of stars that collapsed on their own gravity when the universe was still much younger and denser.
Because the sun evaporates the water out of the clothes
The second statement is the correct choice. Don't make me type it out.
Answer:
valves
The heart has four valves - one for each chamber of the heart. The valves keep blood moving through the heart in the right direction.
Answer:

Explanation:
The formula for force is:

If we rearrange the formula to solve for a (acceleration), the formula becomes

The force is 68 Newtons. Let's convert the units to make the problem easier later on. 1 N is equal to 1 kg*m/s², so the force of 68 N is equal to 68 kg*m/s².
The mass is 2 kilograms.

Substitute the values into the formula.

Divide. Note that the kilograms will cancel each other out (hence why we changed the units).


The acceleration is<u> </u><u>34 meters per second squared.</u>