A class was performing an experiment to discover the pH values of some common household substances. The results of three groups are shown in the table below. Substance Group 1 pH Group 2 pH Group 3 pH Lemon juice 2.2 2.2 2.1 Vinegar 2.8 2.8 8.2 Baking soda 8.4 8.5 8.4 Milk of magnesia 10.2 10.3 10.2 Which statement best describes evidence that Group 3’s data are less valid than the data for the other two groups? Group 3’s pH value for lemon juice is lower than the values of the other two groups. Group 3’s pH value for vinegar is much higher than the values of the other two groups. Group 3’s pH value for baking soda does not exactly match the values of the other two groups. Group 3’s pH value for milk of magnesia is different from the value obtained by Group 2.

c

explanation:

i'm thinking (a) to keep sand in place; ////////////

explanation: a sand fence or sandbreak, like a snow fence, is used to force windblown, drifting sand to accumulate in a desired place. sand fences are employed to control erosion, sand dune stabilization, keep sand off roadways, and to recruit new material in desert areas.

the darker peppered moth species were favored due to the fact that the industrial revolution had made all the nearby trees a darker color instead of white.

"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."