Aids and the bubonic plague are examples of

a.) counter migration stream
b.) migration stream
c.) pandemic
d.) parish

C, most pandemics are considered lethal, but some are not considering small pox use to be lethal as well as a common cold. Yet it is spread through out the world such as usual pandemics.

Humid continental climate is found in the interior of continents between the 30 and 60 degrees latitude, but usually above the 40 degree line.   40 degrees north of the equator means less direct sunlight and therefore less warmth.   this climate is mainly found in the northern hemisphere since there are no major landmasses in the southern hemisphere.  if you live in northern indiana, you know all about humid continental because that is the climate type you have!

Answer volcanic outgassing;