During exercise, the use oxygen faster, so the have to work harder. a. lungs, muscles b. muscles, lungs c. muscles, glucose d. glucose, lungs

What is one benefit of a nonrenewable resource, such as natural gas? a. generate large amounts of electricity b. less expensive overtime c. produces pollution d. will run out eventually

What was the land like over 500 million years ago? what was under the sea?

How can active reading strategies you? o a. they can you get into better physical shape. o b. they can you read fewer science articles. o c. they can you understand what you read. o d. they can you avoid reading altogether.