What kinds of waves study characteristics of Earth's layers?

Explanation:

Scientists use waves to study the different layers of the earth. Usually, they use seismic waves, which are waves generated by earthquakes or nuclear-test explosions. The seismic waves are bent, sped up, or slowed down, or even reflected when they pass through the earth's layers.

g1

choices:

a. g2. b. g1. c. m

cell division has two checkpoints namely, g1

checkpoint and spindle assembly checkpoint. the checkpoint which determines if

division has properly occurred is the g1 checkpoint. at this point, is a damage

in the dna is detected or  the has not reach the optimum size, the cell is

stopped in g1 and is not allowed to proceed to further process.

source:

the tricuspid valve is present between right atrium and right ventricle