Answer:
Egypt was considered isolated because the civilization was only centered along the Nile, and had geographical features that cut it off from the rest of the world.
Step-by-step explanation:
To the north, the Mediterranean Sea allowed communication with Anatolia and Greece, but only by sea, not by land.
To the west, the Sahara desert was a buffer with several nomadic and semi-nomadic tribes. To the East, the Sinai desert and peninsula made communications harder with Palestine, and Mesopotamia, and to the South, the Desert of Sudan made communications hard with Nubia and Ethiopia.
The benefit was a lower probability of conflict or invasion from other tribes, but it also had a drawback and was lesser trade and integration.