part per trillion

例句：

1. 1. The company's stock price has dropped by 5% since the announcement.
   自宣布以来，该公司的股票价格已经下跌了5%。
2. 2.The scientists found that the new drug had a part per trillion effect on the patient.
   科学家们发现，这种新药对病人有万亿分之一的疗效。
3. 3. The project aims to reduce carbon emissions by 80% over the next ten years.
   该项目旨在在未来十年内减少碳排放量80%。