True millions of different species live on coral reefs
Ok here we go:
Science starts with observing which leads to hypothesis, which is tested by experiments.
The other two i am not sure of. Hope i was a help to you. One thing you can do to figure out the other two is google: "what type of science includes medicine and envirnmental science", and do the same for the other one.
Because of the medication that people put in their head so that they can cure cancer
The answer is oil.
The United States' fossil shortage of oil makes the country dependent on outside sources. Mineral oil such as crude oil or commonly known as petroleum came from the ancient fossilized organic materials. This resource is limited. The US is now facing a shortage in oil and becoming dependent to some countries such as middle-east countries.
