Which human activity had the biggest impact on dust storms in 1930 a. diverting rivers and streams b. using industrial pollutants c. replacing natural grasses with crops d. settling in new areas

Which of the following statements about pesticides and residue is false? a. most conventionally grown produce has detectable levels of pesticides when purchased from the store.b. the us government has determined that small levels of pesticides in produce is safe for humanconsumption.c. organic produce always will be pesticide-free.d. farm workers, children, and pregnant women are at greatest health risk from pesticides. select the best answer from the choices provided.

If scientists only detect p waves in a certain layer of earths interior what does that tell us?

Which are evidence of the seafloor spreading? a. molten material b. magnetic stripes c. continental material d. drilled core samples e. ocean water samples