Answer:
the answer should be b ot ccc
The speed of a sound wave depends upon the medium through which it travels. In general, sound travels faster through solids than through liquids or gases. Also, the denser the medium, the slower sound will travel through it. The same sound will travel at a different speed on a cold day than it would on a warm day.
The answer is D. In a
geological era, when the plants and animals
in the then environment die, they get buried
in sediments. These sediments are covered
by other sediments of another geological
time within which are the remains of dead species
of the then geological era. These sediments from different geological times have different properties hence
form visible strata that can be studied to identify the kind of environment in the then geological time. Their
fossils can also be studied to identify
the kind of species that roamed the earth during the time.
