A plant has the genotype AaBb for two characteristics. The genes that control each characteristic are on different chromosomes. The plant produces sperm by a process that begins with meiotic cell division. Which
genotypes will the plant's sperm have?
1.Aa and Bb
2.AB and ab
3.AB, ab, aB and Ab
4.AA, Aa, BB, Bb, AB, Ab, aB and ab

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.

b. lithosphere, asthenosphere, mesosphere   is the answer most likely

when the displaced particles are perpendicular to the direction the wave travels, is called a transverse wave, whereas in longitudinal wave the displace practices are parallel to the direction of the wave.

in the given image:

first image shows - longitudinal wave

second image shows - transverse wave

third image shows - longitudinal wave

fourth image shows - longitudinal wave