Answer:
b) athens was brought to its knees
Explanation:
I believe the answer would be C, burning fossil fuels. Oil and gas is made up of the remains of microscopic plankton. Over millions of years the remains become the carbon-rich coal, oil and gas we can use as fuel. When fossil fuels are burned they release carbon dioxide into the atmosphere, thus contributes to global warming.
A. a system that allowed people to work in return for passage to america
Assuming you mean "undeveloped countries", then the <span>industry in developed countries compares favorable to that of undeveloped countries, since develop countries almost always tend to have more modern and thriving economies. </span>
There were lots of foreign changes that presented challenges for the US. I'll give you a few examples from different time periods. First would be when England wanted to tax the Americans in the Revolutionary period. They did this to try and restrict America's freedom. Another example would be that Russia had spies during the cold war period. This was to gain intelligence of the US war plans. Also when Germany sent the Zimmerman Telegram to Mexico during the WWII period. This was to get Mexico to launch a surprise attack on the US.
