What new technology and strategy of war made Hitler’s invasion of Poland and other parts of Europe so successful?

Explanation:

First of all, it was a land war which Hitler knew how to do best. Germany at the time had an ace Air Force which was his primary weapon in the early part of WWII.

Second Blitzkrieg. Especially against France, that was the most successful strategy. Move everything and move it quickly.  France was stuck behind the concrete walls and couldn't quickly counter punch. France was fighting WWI all over again while Germany moved on to a new and better way of fighting.

the cost of college has risen faster than inflation for many years.

the high price of student services and administration are two reasons for the rapid increase in cost.

you didn't list the options. however, a few communist countries today are: the people's republic of china, north korea, and cuba.