$\begin {array} {1 1} (A)\;\text{ Intermixing of gases} \\ (B)\;\text{Melting of ice below $-4^{\circ}C$ at $1\: atm$ pressure} \\ (C)\;\text{Evaporation of water above} 100^{\circ}C \\ (D)\;\text{Burning of hydrogen in oxygen} \end {array}$
