Answer:
Something that is persistent remains over time; this is a key characteristic of DDT, which also happens to be a pollutant/pesticide. DDT is able to persist in an environment (as a pollutant) in part due to a phenomenon known as biological magnification. In simpler terms. once DDT enters an ecosystem/trophic structure, it gets worse as you go up the trophic levels; in other words, this means that the worst effects/concentrations of the pesticide will be felt in the uppermost trophic levels (your consumers rather than producers).
The basis for this, however, lies in the fact that organisms of a trophic structure/ecosystem consume each other; they feed on each other to survive (e.g. consumers feeding on producers, higher-level consumers feeding on lower-level consumers, etc.). Thus, once DDT gets into an ecosystem, it can only persist and spread in that ecosystem. Hope this helps :)
Life would be quite diffcult! It would be a battle to survive and a lot of people might die. You can’t live without water. Your body needs it
Answer:
it could be the third or last one I'm not sure. choose whichever you think is best.
Answer:A B+ is a 3.3 and a B- is a 3.0. Some schools might weight it differently, though, so it's best to email one of your teachers.
Explanation:
<span>The stars change position in the sky through the course of the night just like the sun changes position in the sky through the course of a day, they rise in the east and set in the west. If you were to start watching a star in the east at the beginning of the night and keep observing that same star for hours, you will see the star's position move across the sky and eventually drop below the western horizon. There some stars that don't rise and set through the night though. The stars near the celestial pole move in circles around the pole. There is one star in the sky that doesn't appear to move at all, because it is located in line with the Earth's axis of rotation, or in other words, on the celestial pole. This star is Polaris, or more commonly known as the North Star. The south celestial pole currently lacks a star so there is no southern hemisphere counterpart. In reality, Polaris isn't perfectly on the celestial pole so even it moves in a very small circle too small to be seen with the naked eye.</span>
