Need !
mars was once similar to earth in that
a. it had only one moon.
b. liquid water flowed on its surface.
c. it showed evidence of plate tectonics.
d. its atmosphere had a thin layer of carbon dioxide.

B. Liquid water flowed on its surface.

Explanation:

We see evidence nowadays that Mars once had flowing water on its outer crust/surface. But due to temperature and different climate changes, the water changed into ice, and some of this water evaporated to space. Hope this helps!

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

answer: blah

explanation:

bc blah