exchange auctions

例句：

1. 1. They exchanged theirold clothes for new ones.
   他们用旧衣服换了新衣服。
2. 2. The company exchangesits shares with the government.
   公司与政府进行股份交换。
3. 3. Exchange rates fluctuate frequently due to global economic conditions.
   由于全球经济状况，汇率经常波动。