Question 1: Banks aim at profit, so buying low and selling high is the principle of banks. Take the direct quotation as an example, 65438 USD+0 = 6.2732-6.2735. Because the former value is less than the latter value, the bank buys foreign exchange (USD) at the former price (6.2732) and sells it at the latter price. Under the indirect pricing method, for example, 1 RMB = 0. 1352-0. 1355 USD, because the front value is less than the back value, banks can only buy less foreign exchange (USD) with the same RMB, so the front value is the bank's selling price and the back value is the buying price under the indirect pricing method. (It's essentially the same as this, buy low and sell high)

The second problem: inflation (that is, the rise of P) is not conducive to exports (because commodity prices rise, the exchange rate remains unchanged, and commodity prices priced in foreign currencies rise, which is not conducive to shipments), and imports are affected by Y, so it remains unchanged. When inflation occurs, domestic prices rise, and then spread abroad through the transmission mechanism, so it depreciates at home first.