threshold sound intensity

例句：

1. 1.The threshold of light intensity is critical for the survival of many organisms.
   光强度的阈值对于许多生物的生存至关重要。
2. 2. The researchers found that the threshold for detecting the virus was very low.
   研究人员发现检测病毒的阈值非常低。
3. 3. The company's threshold for accepting new customers has been raised to 5000.
   该公司接受新客户的阈值已提高到5000。