back shu points

例句：

1. 1.The stock market is a good place to learn about the economy.
   股票市场是了解经济的好地方。
2. 2.The company's stock price has been rising steadily since the announcement.
   自宣布以来，该公司的股票价格一直在稳步上涨。
3. 3.Back points are used to calculate the interest rate on loans and investments.
   背数用于计算贷款和投资的利率。