The correct statements about warm currents are:
A: They are surface currents - True. Warm currents are typically found at or near the surface of the ocean.
D: They make landmasses warmer - True. Warm ocean currents can raise temperatures in coastal regions, leading to milder climates.
B: They move from the poles to the equator - False. Warm currents generally move from the equator toward the poles.
C: They are denser than cold currents - False. Warm currents are less dense than cold currents.
So, the correct answers are A and D.