What is an important characteristic of the plant cell wall?
a.) it is fluid.
b.) it is rigid.
c.) it is alive.
d.) it stretches.

Which plains area lies in both the united states and canada? altiplano central canadian shield coastal plains great plains

18. over time, how do sand dunes tend to migrate? a. perpendicular to the movement of the wind b. in the same direction as the wind blows c. toward the wind d. in random directions

How can we use spectral lines of light coming from the superclusters to identify which is receding from earth at the slowest rate.