Pls answer

in the formula:
fm=k m1m2/r2
r is the distance:

a) from the north pole
b) between poles m1 and m2
c) from m1 to the nearest magnetic body
d) between the magnetic lines of force

radiation warms things up temp rises convection currents air circ windy weather

myth. it was once thought that animals, including cats and dogs, could only see in black and white. however, scientists have proven this to be a myth. in all animals, including humans, the perception of colour is determined by the presence of cells in the eye called cone photoreceptors.