sell low buy high

例句：

1. 1.We should sell low and buy high tomake a profit.
   我们应该低价卖出，高价买入以获利。
2. 2. The stock market is always ina state of high-low fluctuations.
   股市总是处于高低位波动状态。
3. 3. He boughtthe house at a low price and soldit for a high one.
   他以低价买入了房子，然后以高价卖出。