The right answer is A. sismic waves.
Seismic waves correspond to elastic waves that propagate on the surface and inside our planet following an earthquake.
They appear when a starting impulse sets particles in motion, which in turn will move the material to their contact before returning to their original place. The generated phenomenon can then spread over tens, hundreds, even thousands of kilometers. Note that these waves can be generated artificially in seismic studies.
Like all waves, they can be reflected or refracted when they pass from one medium to another (for example between the mantle and the Earth's core).
The answer is Fibre. Fibre can add bulk (expand when meet water) to our food therfore it can stimulate the peristalsis (movement) of intestine to prevent constipation.
The process that Darwin described as "descent with modification" is the process of evolution.
"Descent with modification" is one of the fundamental ideas behind Darwin's theory of evolution. According to Darwin, the characteristics of an organism are inherited. Offspring with inherited characteristics which allows them to compete best with the limited resources in the environment will survive. Organisms will pass the traits providing an advantage to survive and reproduce to the next generations. Over time and generations, the traits providing reproductive advantage will become common among the polpulation. This will lead to change in populations over generations in a process called the "descent with modification".
Answer:Its B
Explanation: Hope this will help