What are the two main sources of energy that power the Earth system? A. the sun and Earth's interior
B. radioactive decay and volcanic eruptions
C. the sun and the motion of Earth through space
D. the sun and human activities, such as burning fossil fuels

The answer is A, the sun and the Earth's interior.

A.the sun and Earth interior

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."

multiplying and dividing the two decimals and the eqations by the same number of the overalls