I don't know a lot about volcanos, but I can help you with the formatting
I choose the option C.
N2 + 3H2 = 2NH3
Warm-blooded creatures, like mammals and birds, try to keep the inside of their bodies at a constant temperature. They do this by generating their own heat when they are in a cooler environment, and by cooling themselves when they are in a hotter environment. To generate heat, warm-blooded animals convert the food that they eat into energy. They have to eat a lot of food, compared with cold-blooded animals, to maintain a constant body temperature. Only a small amount of the food that a warm-blooded animal eats is converted into body mass. The rest is used to fuel a constant body temperature.
I am not entirely sure what you mean by "responding variable" but I'm going to guess it was the vinegar since it has been used as a perservative for years.
Hope that helps in some way.
Answer:
C
Explanation:
Membranes will allow and inhibit certain ions/molecules. I don't believe it can distinguish whether the molecules are harmful or beneficial!