[填空题]
A Carnot engine performs wo gukjk enr-rab9,-1f 7: qf:dxrk at the rate of 440 kW while using-h sp-8vxnxi4 680 kcal of heat per second. If the temperature of the heat source is v ih48-pxns x-570$^{\circ}\,C$, at what temperature is the waste heat exhausted? $^{\circ}\,C$
