When does fluvial erosion begin? a. when rain falls on flat or sloped surfaces b. when water flows into the ground c. when rills develop d. when water flows downslope?

What element does susan b. anthony include in this passage to strengthen her argument?

Which best describes a benefit of using dna technology in medicine? a) medicine can be produced in mass quantities. b) medicine can be distributed at a reduced cost. c) medicines have fewer side effects. d) medicines are resistant to antibiotics.

How do all types of diffusion/passive transport actually ‘work’ without using even the smallest amount of cellular energy?