15. How do cows contribute to global warming? O A. They both produce and use up greenhouse gases.
O B. They have enteric fermentation and release methane.
C. They purify the air by breathing in greenhouse gases.
O D. They have enteric fermentation and the microbes in their guts break down
greenhouse gases.

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.