For my homework i was given this: find an example when each of the 3 branches of the national government has checked one of the other 2. i cant find anything on the internet

There are lots of examples here:

http://www.google.com/search?hl=en&source=hp&q=checks+and+balances+examples&aq=0&aqi=g3g-m3&aql=&oq=checks+and+balances+exam&gs_rfai=CYx5Psm2NTLLxO4-UoATIwPmkBgAAAKoEBU_QkHyT