Why are Earth's materials and energy considered to be in equilibrium? (Select all that apply)

Earth's materials are recycled and reused constantly
Earth's materials are all divided in equal amounts
Energy is balanced and cannot be created or destroyed
O Energy is always converted into usable forms

In this case, the statement that people who exercise for an hour may have lower cholesterol levels is .

The pharynx is the structure in the body that serves as a pathway of both air and food. how does the body make sure that food does not get into the lungs? the salivary glands secrete enzymes that pull food out of the air pathway. the small intestine pushes the air out of the digestive system. the pancreas breaks down food in the air pathway. the epiglottis closes the air pathway so that food will not enter it.

What is the main reason that attitudes are more often revealed in spoken rather than written language? a. in writing, we try to put the "best face" on what we write. b. we speak far more often than we write. c. in writing, we can more easily conceal our attitudes. d. in spoken language, we are often careless in our use of words.