grain refining

例句：

1. 1. The process of grain refining is crucial for the food industry.
   谷物精炼过程对于食品工业至关重要。
2. 2. Grain refining technology has greatly improved the quality of rice and wheat.
   谷物精炼技术大大提高了稻米和小麦的质量。
3. 3.During grain refining, the starch in the grains is converted into sugar, which is then used as a sweetener.
   在谷物精炼过程中，谷物中的淀粉被转化为糖，然后作为甜味剂使用。