Question

text 1
ancient egyptians created one of the earliest known devices for measuring time: the sundial. sundials were designed so that a shadow would be cast at different angles as the sun moved. the passing of time could be observed by watching the shadows position change. since sundials relied on sunlight to create shadows, the device could not always be used to tell time. sundials did not work at night or on cloudy days.

text 2
ancient egyptians developed a timekeeping device called a water clock. a water clock consisted of two stacked containers. the upper container was filled with water, which then dripped into the lower container. the steady rate of dripping was a dependable measure of time. people could tell how much time had passed just by measuring the water levels. for example, one inch of water in the lower container might represent one hour.

which sentence best combines the main, or central, ideas of both texts?
ancient egyptians created different ways of measuring time, using natural resources like water and sunlight.
ancient egyptians were able to tell time with the invention of clocks, but their clocks only worked during the day.

Explanation:

Text 1 covers the sundial, an ancient Egyptian timekeeping tool using sunlight, while Text 2 covers the water clock, another Egyptian timekeeping tool using water. The correct combined sentence must include both distinct methods and their natural resource bases, and exclude incorrect claims (like all clocks only working in the day, which is false for water clocks).

Answer:

Ancient Egyptians created different ways of measuring time, using natural resources like water and sunlight.