Which of the following explains why elements, such as carbon and nitrogen, are never permanently removed from the environment?
a. They are replenished by sunlight.
b. They are replaced by volcanic eruptions.
c. They are produced constantly by nutrients.
d. They are cycled through ecosystems.

City a and city b had two different temperatures on a particular day. on that day, four times the temperature of city a was 8â° c more than 3 times the temperature of city b. the temperature of city a minus twice the temperature of city b was â’3â° c. what was the temperature of city a and city b on that day? city a was 5â° c, and city b was 4â° c. city a was 3â° c, and city b was â’1â° c. city a was 8â° c, and city b was â’3â° c. city a was 5â° c, and city b was â’5â° c.

What type of reaction fuels the processes seen here?

Structure of the atoms: discovery of the nucleus in 1909i need answering all of these questions