Which activity released the most carbon between 1750 and 2012

Making cement
Burning fossil fuel
Mining coal
Cutting down trees

Did the vinegar diffuse all the way to the center of any of the cubes? if so, which ones? what does this tell you about surface area-to-volume ratio and the diffusion rate?

The relationship between intron and exon

The human body needs energy in order to carry out life processes such as breathing. where does the body get this energy? a. from eating food b. from learning about new things c. from lying in the sun d. from sleeping