Which of the following demographic changes is not the likely result of a natural disaster? a significant reduction in the population of the young occurs because they are more vulnerable to infectious diseases spread by unsanitary conditions. birth rates rise dramatically during droughts and famines, unlike in other natural disasters. population declines because families tend to migrate away from places after a large disaster occurs. a significant reduction in the population of the elderly because they are more vulnerable to infectious diseases spread by unsanitary conditions. population declines because natural disasters act as a push factor driving people away from the area.

I think the answer is A significant reduction in the population of the young occurs because they are more vulnerable to infectious diseases spread by unsanitary conditions.

In my opinion, unsanitary conditions are often man-made. For example, if a person does not clean his surroundings, this would cause bacterias from infecting the place. Then it affects the person living in that area, then spreads because through oral or sexual contacts. 

Answer dot(3) is most used;

You need to figure out at which x-value does the graph has a tangent line slope of -1.remember, the derivative is the slope of the tangent line. so find the derivative function and set it to equal -1 to find the x-value that will have a tangent line slope of 0.differentiate with the chain rule.    set the derivative to equal -1 and solve for x.      take log base 10 of both sides. also recall that  .    so the x-coord of the point of tangency is .the y-coordinate of this point of tangency can be calculated using the original function:     using point-slope form, the equation of the tangent line is      the x-intercept of this tangent line is when the graph is at y=0.    this rounds off to  .choice c.