HELLP ITS THE HIGHLIGHTED ONE

Which phrase best describes surface currents? 1. up-and-down ocean movement caused by wind 2. waves that hit the shore at an angle and transport sand 3. streams of warm water flowing through the ocean and caused by wind 4. waves that approach the shore and cause their crests to fall into their troughs

Can create a hboth of these instruments can measure wind speed. doppler radar and psychrometer anemometer and hygrometer doppler radar and anemometer radiosonde and psychrometer

Which of the following statements is true about the relationship between genetic variation and natural selection? a. genetic variation must be present in a population before natural selection can act on it. b. genetic variation arises in a population as a result of natural selection. c. natural selection can act on a population whether there is genetic variation within the population or not. d. after natural selection acts on a population, the amount of genetic variation in the population always increases.