Answer:
400
Explanation:
Because if you pull one black marble out of four and there are 100 black marbles then there is 300 others, so in total it would be 400 marbles.
thanks if i'm given brainliest!!!
Answer: Natural selection is one of the forces of evolution and the enviroment where the species lives is the selection agent. For example, suppose a mosquitoes population in a environment free from insecticides, in this environment there's a high frequency of non-resistant mosquitoes because the environment is not exerting any pressure on the resistence trait. But when the environment changes and we use a insecticide upon the mosquitoes population, the populations changes because the non-resistant ones die but those resistant survive and beggin to reproduce more effectively. That's natural selection, differences in survival and reproduction between individuals with different phenotypes (traits) and this differences depend of environmental changes.
Answer:
Umm... in the oceans, the waters absorb heat from the sun and the currents carry it to other locations.
<span>physical agents are mechanical forces that produce injury or tissue trauma. some examples of this are extremes of temperature (burns and really deep cold), sudden changes in atmospheric pressure, radiation, and electric shock.</span>
