The doldrums along the equator is an area of very little wind. This gave early sailors a difficult time in their transoceanic trips. How could sailors avoid this trouble spot?

It's probably because some types of violets are blue

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!

Answerepicenter;

Answer volcanic outgassing;