What's the difference between primary source and secondary source

Averb diagram that shows the similarities and differences of two african kingdoms

It can be inferred that the dramatic increase in defense spending by germany was the result of. (a) attempts by great britain to take german colonies. ( b) fear of a two-front war against france and russia (c) the need to put down a communist rebellion (d) a competition with the allies to produce atomic weapons

Even though the u.s. was not at war roosevelt met with great britain to sign this secret pact that neither country would seek territorial gains after the war. a atlantic charter c. potsdam charter b. yalta charter d. london charter