What is the estimated age of the earth according to scientists?
a. 12.2 billion years
b. 4.6 billion years
c. 660 million years
d. 3.5 billion years

Awater molecule is polar because there is an uneven distribution of these between the oxygen and hydrogen atoms.

Which of the following is not a potential result of deforestation?

Which is an important function of normal flora? a. aid with bone marrow production. b. crowd out pathogenic bacteria. c. destroy digestive track pathogens. d. manufacture iron in the bloodstream.