Answer: C) extremely rapid cooling
Explanation:
When magma goes through extremely rapid cooling and especially if it did not dissolve enough water into it, it could freeze to glass or the mineral crystals that will be formed will be so small, they will look like glass.
This is because the reactions that occur to create minerals are affected directly by temperature such that if the magma cools down extremely slowly, it will form very large crystals but extremely fast would result in small crystals.
Decomposers are necessary to the food chain because they break down the results of the food chain into the basic elements that producers can then use to begin the process over again. Decomposers include groups of bacteria that help to speed up the decaying process of dead plants and animals.
Hope that helped! =)
Answer:

Well, you can take the example of different genres of music. One person might like pop while others might be more interested in country, jazz, hip hop etc. So, what seems good for one might not seem good for others due to their tastes in different things.

In a way, this is a double edged sword. On one hand, the animals are needed to best test the effects, but on the other hand it can be seen as very unethical. Honestly, I don't really see a way around using the animals. Unless you get human volunteers, but there is no way to fully make them understand what they are getting themselves into which can turn unethical very, very fast. If all of a sudden one of your human volunteers decides that they do not want to be a part of the test anymore, there is noting you can do to reverse what has already been done.