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: 
Explanation:
The Tropic of Cancer is one of the parallels (imaginary line around the Earth parallel to the equator) located in the northern hemisphere (currently its latitude is 
).
It is called "Cancer" because a long time ago, when the summer solstice occurred in the northern hemisphere (on June 20th or 21st), the Sun was in the constellation Cancer (the crab).
Now, if we were just in the North Pole, Polaris would by exactly over our heads (
over the horizon), but as we go south and find the Tropic of Cancer parallel, Polaris altitude will be approximately at an angle of over the horizon.
Hence, the altitude of Polaris measured by an observer at the Tropic of Cancer is .
B is correct because the others are wrong, c is wrong because the reason they have varying states of matter is because pressure and a is wrong because mantle
The correct answer is - the air.
The Namib Desert is one of the driest places on the planet and that is due to the cold and dry ocean currents alongside the southwestern part of Africa which are not providing the right conditions for precipitation to occur.
Even though there's no rain, because the Namib Desert is very hot, and the ocean currents very cold, the end result is mist that appears every morning, as well as dew.
The plants living in this desert have evolved in accordance to the conditions, so instead of being dependent on their roots for getting water, they get the majority of the water through their leafs and skin, directly from the air.
