In very early human history, complex sanitation systems were not needed because settlements were usually very small, like the village shown below. however, as cities became larger and population densities increased, one major advancement was the development of which to channel wastewaters away from human populations more effectively than in the past.

Hannah is writing a report on how albedo affects the global climate. she’s proofreading her passage for any factual errors. which sentence must hannah correct before submitting her report? earth receives energy from the sun. this energy drives many of the processes on earth, including its climate. some part of this energy is reflected by earth’s surface. we use the term albedo to describe the reflected energy. albedo of an object is the ratio of the reflected radiation to the total radiation reaching the object. a value of 0 means no energy is absorbed by the object, whereas a value of 1 means that all of the energy is absorbed. in this way, the albedo of an object can influence earth’s atmospheric temperature.

How did planetesmals form planets? a. they broke apart into smaller chunks. b. they collided and stuck together. c. they cooled and pulled ice together. d. they began to rotate.

Arecipe calls for 1.2 cups of oil. how many liters of oil is this?