Because of the coronavirus crisis, the Korean won/dollar exchange rate depreciated rapidly. The bank of Korea does not want this depreciation of the domestic currency, so the central bank does implement a foreign intervention to prevent too much depreciation. Please explain the mechanism of the foreign intervention verbally and graphically. Moreover, the central bank does not want to increase the interest rate due to the intervention policy, therefore, they decide to implement a sterilization policy to make money supply unaffected. Please explain the sterilization policy in the graph.