The surface area of a sphere can be approximated as follows:

surface area = 4πr2;
where r is the radius of the sphere;
π is a constant that is roughly equal to 3.

calculate the surface area of a sphere with a radius of 7 meters using the simple approximation above.

i think that d. wind is the answer.   i missed the question when i answered a. currents.

"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."