Ascientist wants to examine a genetic disease in humans. the scientist hypothesizes that the disease can be treated by using gene therapy. humans take a long time to reproduce and develop, so the scientist will have to give up on testing the hypothesis. test the hypothesis for a very long time. develop new methods to test the hypothesis. find a way to make humans reproduce faster.

Gene therapy can be defined as the medical procedures that target genes in order to treat disorders and diseases

Explanation:

Perhaps the most common experimental technique in genetics is to use phylogenetically related animal species as experimental models (such as mice), which have short generation times

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.

i believe it would cause an increase of percipitation, though i could be wrong. so i would say b is the answer.