What happens if the earth consist of pure oxygen

Well, oxygen itself isnt flammable, but it is what means that everything else can burn. So if the whole atmosphere was oxygen then things would be really easy to set fire to and then everything else flammable would set fire around them too.

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!