Answer: In Stage 4 of the Demographic Transition Model birth rates and death rates are both low, stabilizing total population growth. The decline in both birth and death rates of most Stage 4 countries have been attributed to strong economies, highly educated citizens, ample healthcare systems, the migration of people from rural communities to cities (Bulgaria)
Explanation: i dont know if it's correct to them
Your answer would be A because none of the others make sense, Hope that helps!
Answer:

Explanation:
Straight wings are dominant over curved wings
Let Straight wings : H
curved wings : t
smooth eyes are dominant to sparkling eyes
let smooth eyes = H
spark ling eyes = t
tan body is dominant to ebony body color.
Again; Let tan body color be H
Let ebony color be t
If flies that are heterozygous for all three traits are crossed;
we have HtHtHt × HtHtHt
Then the selected trihybrid traits for the cross will be (HHH,HHt, HtH, Htt, tHH, tHt, ttH, ttt)
We will realize that from the punnet square in the diagram below, the proportion of the offspring would you expect to be heterozygous for all three traits (i.e HtHtHt) is asterisk in the punnet square and will be 
= 