The scale scientists use to estimate the rate of change in proteins over time is called a a. protein meter
b. common estimator
c. chemical ruler
d. molecular clock

stress fractures occur largely in the feet and legs and are common in sports that require repetitive impact, primarily running/jumping sports such as gymnastics or track and field.

i think that it is plants

links? do you have a link? i don't see anything?

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this