What idea did Jean-Jacques Rousseau write about?

Which of the following is one example of an ideological conflict that became one of the causes of world war ii?

Match each treaty with its description. treatys- a the munich agreement b the pact of steel c the molotov-ribbentrop pact descriptions- 1- an alliance between germany and italy 2- an agreement between germany and the soviets dividing eastern europe 3-an agreement between germany, france, italy, and britain granting germany a small part of czechoslovakia in return for peace

Why might it be important to know a currency’s exchange rate