Why did the hundred years war last so long?

Which four of these developments were made under mongol rule during the pax mongolica? the extension of the grand canal in china the spread of christianity the spread of weapons that used gun powder the invention of new medicines the establishment of a postal system the invention of geometric models of lunar motion

In the 100 years after haiti gained independence, its government could be the best described as unstable. powerful. stable. unifying

The land bridge and coastal crossing theories concern the earliest human migration from