在浮动汇率的蒙代尔—弗莱明模型中，解释当取消了对进口汽车的配额时，总收入、汇率和贸易余额会发生什么变动。

如果汇率是固定的而不是浮动的，会发生什么变动？

In the Mundell-Fleming model with floating exchange rates, explain what happens to aggregate income, the exchange rate, and the trade balance when a quota on imported cars is removed. What would happen if exchange rates were fixed rather than floating？