Sub-saharan africa's population growth is

1.decreasing
2.negative
3.positive
4.stagnant

3.positive

Explanation:

According to new researches the population of the  subsaharan african region is incerasing and will be the region that will increase the most its population, doubling its population in the next 20 years, from 1.1 nbillion to 2.4 billion in 2050 approximately. This means that the population growth is positive.

two jet streams that directly affect the formation of weather in the continental part are a polar jet and a subtropical jet. they are responsible for the transportation of weather systems, which directly affect people. the polar front is the boundary between cold air from the north pole and warmer equatorial air. both the polar jet and the subtropical jet blow from the west to the east, and follow the boundary between cold and warm air.

the strongest jet streams are polar jets, while subtropical jets are somewhat weaker.

the right answer is c. the polar jet stream is generaly stronger than the subtropical jet stream.

answer; answer; marginal cost;