Alcohol is considered a gateway drug because: a. when people drink, their judgment diminishes, and their ability to make good choices is impaired. b. under the influence of alcohol, people get more daring and more willing to try things they would never try if they didn't drink. c. both a and b

Option C, Both A and B

Explanation:

A gateway drug is one which if consumed regularly will make the user daring enough to try much harmful drugs such as cocaine, marijuana etc. Hence, a gateway drug is one which opens gate for a person to use more harmful and varied drugs. Such as alcohol,nicotine etc.

Under the affect of gateway drug a person is unable to make right and conscious choices and hence he/she becomes impaired.

Thus, option C is correct

4.) metal

"-the movement of carbon from the nonliving environment into living things and back to the environment

-carbon is the essential component of proteins, fats, and carbohydrates (which make up all organisms)

-carbon exists in air, water, and living organisms

-producers convert carbon dioxide in the atmosphere into carbohydrates during photosynthesis

-bacteria in the atmosphere cycles through the system in filtration units

-in cellular respiration, carbon is released back into the atmosphere as carbon dioxide

-some carbon is stored in limestone (forming one of the largest "carbon sinks" on earth)

-largest carbon reservoir on earth= limestone

-carbon stored in the bodies of organisms as fat, oils, or other molecules may be released into the soil or air when the organism dies

-this may form deposits of coal, oil, or natural gas (fossil fuels, which increased the atmospheric carbon dioxide)

-fossil fuels store carbon left over from bodies of organisms that died millions of years ago

-they are located in the surface of earth, deep within the earth and beneath the ocean floor."