The sunk cost is the cost that has been paid and is not recoverable. The sunk cost is determined by past decisions or the environment, and the cost caused by it cannot be changed by any decision now or in the future. Based on the above definitions, what does the following not involve sunk costs? ['Xiao Li bought a second-hand desktop computer for $ 100.', 'The coal of a coal mine has been mined and some mining equipment in the mine has to be abandoned because it cannot be taken out.', 'If Xiao Chen had stocked the pheasant in the contracted mountain forest, he had more annual income than stocked hare, but had more management, so he chose to stock the hare.', 'Xiao Zhang is going to ask Xiao Li to go to the movie together, because Xiao Li works overtime temporarily, and she cannot refund the ticket. Xiao Zhang has to use two movie tickets as a message box.']