Abridge most nearly means:

For the fuel to travel from Reservoir A to Reservoir B, passing through Filters C and D on the way, which valves must be open?

Erosion and depletion are problems associated with

An employee of a chocolate factory earns $7.20 an hour. She is paid time and a half for overtime beyond a
40-hour week. How much will she earn in a week in which she works 43 hours?

History tells us that Christopher Columbus once saved his own life because he knew from his almanac that there was going to be an eclipse of the moon. In 1504 Columbus was marooned in Jamaica with no food and unfriendly natives confronting him. The explorer threatened to turn off the light in the sky if the natives refused to give him food. Columbus kept his word; the natives gave him food.
The main idea of this paragraph is that