Why was Rosetta Stone important to historians

Rosetta Stone helped scholars crack the code of hieroglyphics, the ancient Egyptian writing system. French army engineers who were part of Napoleon Bonaparte's Egypt campaign discovered the stone slab in 1799 while making repairs to a fort near the town of Rashid

Explanation:

two jet streams that directly affect the formation of weather in the continental part are a polar jet and a subtropical jet. they are responsible for the transportation of weather systems, which directly affect people. the polar front is the boundary between cold air from the north pole and warmer equatorial air. both the polar jet and the subtropical jet blow from the west to the east, and follow the boundary between cold and warm air.

the strongest jet streams are polar jets, while subtropical jets are somewhat weaker.

the right answer is c. the polar jet stream is generaly stronger than the subtropical jet stream.