Density, because the core is made of metals like iron and nickel
Temperature and density increases from the crust to the core.
Answer: Water pollution can have disastrous effects on the environment.
Explanation:
- Pollution in the water can reach a point where there isn't enough oxygen in the water for the fish to breathe. The fish can suffocate and not have enough air.
- Pollution affects the entire food chain. Small fishes absorb pollutants, such as chemicals, into their bodies. Bigger fishes eat the smaller fishes and get the pollutants as well. Birds or other animals may eat the bigger fishes and be harmed by the pollutants. One example of this was the use of the insecticide (bug killer) DDT, which is when birds of prey ate fishes that were infected with it, they would lay eggs with thin shells. The population of birds of prey began to drop until DDT was banished.
- Sewage causes major problems in rivers. Bacteria in the water will use oxygen to break down the sewage. If there is too much sewage, the bacteria could use up oxygen until there won't be enough left for the fish.
- Water pollution from major events like acid rain or oil spills can completely destroy marine habitats.
- One of the most important commodities for life on planet Earth is clean water. For over 1 billion people on the planet, clean water is nearly impossible to get. Dirty, polluted water can make them sick enough to die.
Answer:
A. 74
Explanation:
The given mortality rate is understood to be <em>deaths per thousand per year</em>. So, among 10 thousand people, one might expect 10×7.4 = 74 deaths per year.
