(A) $1.$ True. For an adiabatic process,the relation between temperature $T$ and volume $V$ is given by $T V^{\gamma - 1} = \text{constant}$.
$2.$ True. The charging of a battery is considered a reversible process if it is done infinitely slowly without any energy dissipation.
$3.$ False. Water falling from a height is an irreversible process because the kinetic energy gained is dissipated as heat due to friction and impact,which cannot be recovered.
$4.$ False. Internal energy,volume,and mass are extensive variables (they depend on the amount of matter),whereas pressure,temperature,and density are intensive variables (they are independent of the amount of matter).