standard heat of combustion

例句：

1. 1.The standard for measuring the height of atree is 20 feet.
   测量树高的标准是20英尺。
2. 2. The companyhas adopted a new standard for product quality.
   该公司已采用新的产品质量标准。
3. 3. Thestandards for education in this country are veryhigh.
   这个国家的教育标准非常高。