<span>Virginia Coastal Plain.
In addition to the rich fossil finds mentioned, these rocks also include some mastodon fossils which can be found in Quaternary sediments deposited along lakes and rivers.</span>
Easy. Answer is oxygen because it says which one was missing before any life was on earth. And in order to have life on earth you need oxygen!
:)
In order to determine the results from a father who is homozygous recessive for the tongue rolling trait, T, and a mother who is heterozygous for the trait, a Punett square can be used to determine both the resulting genotype (allele combination) and phenotype (observable characteristics). The results are 50% Tt and 50% tt. Thus, the cross would result to 1:1 ratio of tongue rolling to non-tongue rolling offsprings.
Answer: 0.69 m/ mile.
Explanation:
The altitude gradient between two cities X and Y = 
Given: Two cities are separated by 200 miles.
City X has an altitude of 122 meters.
City Y has an altitude of 260 meters.
The altitude gradient between two cities X and Y =

Hence, the altitude gradient between the two cites = 0.69 m/ mile.
When homeostasis is not maintained, the body cannot function properly and illness may ensure. Homeostasis is the process in which the body's overall internal environment is kept constant in response to any external environmental changes. This involves maintaining stability in different body systems.