do not remove grass!

signs like this appear all over coastal regions. why?
a) the grass holds moisture in the ground.
b) the grass provides shelter for many animals.
c) the grass to keep the sand dunes in place.
d) the grass to keep the air temperature constant.

It's C

Explanation:

The grass helps to keep the sand dunes in place. The roots of the grasses spread out to anchor the plants and the same roots help keep the sand in place. The beach grass is stopping erosion by wind.

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.