The advancement that enabled the egyptian civilization to survive the arid desert conditions was

The answer is

Irrigation

Explanation:

Climatic changes and the considerable reduction in rainfall obligated the populations and animals to concentrate in areas closer to water (rivers). The need for survival of these groups led to the creation of agriculture and consequently to the development of irrigation techniques, expanding the cultivable area. In the case of Egyptian Civilization, they had to understand how to deal with the Nile floods. During the flood season (July and October), the river deposited on its banks a fertile mud called humus, where cereals and vegetables were planted. A complex network of canals was built to divert water for irrigation, and dams to store.

from the conditions of the working class in england by friedrich engels,the main idea is :

d.

the northwest territory became the most densely populated area in the u.s.