PART A: Which of the following phrases best expresses the central idea of the article? A.
Egypt would have developed civilization sooner if they built canals that forced
the Nile River to flood less often.
B. The natural environment protected Egyptians from invaders and also played a
critical role in their development of agriculture and calendars.
C. Egyptians would not have been able to predict the Nile's flooding without the
invention of papyrus paper.
D. The desert was an important resource because it not only provided protection
from invaders, but also rocks for building and salt for trading.

B. The natural environment protected Egyptians from invaders and also played a  critical role in their development of agriculture and calendars.

Explanation:

The natural environment around Egypt was crucial for the development of the Egyptian civilization, due to two main reasons.

One reason is the Nile River, which was the central artery of Egypt, and crosses the territory from North to South, with a huge Delta in the extreme north. The Nile flooded the banks seasonally, leaving the soil with rich sediments that had many nutrients and that made the land more fertile. This allowed the development of agriculture, the founding of cities along the banks, and the establishment of the Ancient Egyptian Civilization.

The other reason is that this central heartland along the Nile was surrounded by deserts or by the Mediterranean Sea. This made Egypt hard to invade, and although it was invaded a few times, no invasion could ever destroy the Egyptian Civilization until the Romans, when Egypt had already more than 3 thousand years of history.

on this day in 1913, henry ford installs the first moving assembly line for the mass production of an entire automobile. his innovation reduced the time it took to build a car from more than 12 hours to two hours and 30 minutes.