Organisms are classified as living things, rather than nonliving things, based on specific characteristics. one of those characteristics is the ability to grow and change. which of these is the best example of a living thing showing this characteristic?
a) a mother lion nurses her cubs in the safety of a den.
b) a bear's heart rate lowers to conserve energy during winter.
c) a pupa forms around a caterpillar as it morphs into a butterfly.
d) a squirrel collects and stores acorns and nuts in a tree for winter.

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.