Positron Emission Tomography scan of the brain of cocaine addicts showed that the drug affects how the brain use glucose. Cocaine users' brain cannot use glucose efficiently and there are also reduced metabolic activity in other areas of the brain.
D. Asteroids vary greatly in size and are mostly made up stone, iron and nickel
The most prominent example of carbon fixation is photosynthesis
C. Temperature and pH can affect how enzymes work.
