The united states experienced a record number of measles cases during 2014, with 668 cases from 27 states reported to cdc's national center for immunization and respiratory diseases (ncird). this is the greatest number of cases since measles elimination was documented in the u. s. in 2000. the people, most children, contracted measles a) because they were not vaccinated. b) due to impoverished living conditions. c) they were immigrants, not u. s. citizens. d) because they lived in very tight quarters.

A) because they were not vaccinated.

Explanation:

Measles is a dangerous and highly contagious disease, which is characterized by high fever and spotting on the body. Our body has no natural defenses against this disease, and the most efficient way of not being infected by it is through vaccines.

Measles has gone years without being a real threat to humanity, but unfortunately the anti-vaccine movement has grown worldwide. This movement meant that many parents did not allow their children to get the measles vaccine, which made them susceptible to the disease that once again threatened humanity, especially in countries like the USA and Brazil, for example.

c

explanation:

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."