A thermodynamic system is taken from state A to state C along either path ABC or path ADC. Along path ABC, the work done W by the system is 450 J. Along path ADC, W is 120 J. The internal energies of each of the four states are U_A= 150 J, U_B= 240 J, U_C= 680 J and U_D= 330 J. Calculate the heat flow (Q) for each of the four processes AB, BC, AD and DC. In each process, does the system absorb or liberate heat?