I’d say A is probably the correct answer , but if not A , then definitely B.
The answer is A, because the phytoplankton is the foundation of this food web. Without your foundation, "the building will begin to crumble".
The correct answer is - predator species in a community.
In the terrestrial ecosystems, a very good and usually sure predictor of the biodiversity is the existence of a predator species. The more predator species there are, the higher the biodiversity, and vice versa, the less predator species, the lesser the biodiversity.
The reason why the predators are such a good predictor of the biodiversity is that they are the species that are on the top of the food chain. That means that the predators are dependent for their survival on all the other species bellow them in the food chain, which is pretty much all species apart from themselves.
If a predator is present, than there has to be pray. If there's pray, omnivores and herbivores, than there has to be plants. All of the organisms are connected to one another, and the ones on the top of the food chain are the most dependent on the others, thus their existence usually means a healthy ecosystem with higher biodiversity.
The correct answer is multiple sclerosis.
The MS or multiple sclerosis refers to a demyelinating disorder in which the insulating envelopes of the nervous tissues in the spinal cord and the brain get destructed.
This destruction disturbs the tendency of the components of the nervous system to interact, leading to an array of symptoms and signs, involving mental, physical, and on certain occasions psychiatric issues.
The correct answers are:
A. People enjoy cruise vacations;
B. People need to cross the ocean;
E. People need to earn a living;
The vessels that are going through the ocean waters are both very useful and damaging in the same time, depending on the perspective. From one side, lot of people use them as a mean of traveling from one side to the other side of the ocean, millions of people enjoy going on vacation on the ocean/sea cruises, and also millions of people are employed and make a living from those vessels. On the other hand, all of the sewage from those millions of people is released into the ocean waters, thus causing pollution of the waters, which effects the marine life and its well-being.
