Explain the principle of checks and balances as it relates to the power of the president provide one example to support your explanation

The principle is that any part of the government cannot become to powerful, because they have to be "checked" by other parts of the government.  One example is that congress has to approve the president's nominations for the judicial branch. The president can also veto congressional legislation.

supplies had to travel a long distance across water on ships that were often attacked, so they did not reach europe