The diagram shows two charged objects, X and Y. Based on the field lines, what are the charges of the
objects?
O X: positive
Y: negative
O X: negative
Y positive
O X: negative
Y: negative
O X: positive
Y: positive
x
Y

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.