Most of us already know that darkness<span> is the absence of light, and that light travels at the fastest </span>speed<span>possible for a physical object. So, what does this mean? In short, it means that, the moment that light leaves, </span>darkness<span> returns. In this respect, </span>darkness<span> has the same </span>speed<span> as light</span>
Answer: The cause can be something that causes the problem and the effect is what effected it. If something caused the population to go down the effect would be death rate or birth rate.
