cross substitution

例句：

1. 1. In the study, researchers used a cross-substitution method to test the effectiveness of their new drug.
   在研究中，研究人员使用交叉替代方法来测试他们新药的有效性。
2. 2. The company's decision to cross-substitute its products with cheaper alternatives has raised concerns about sustainability.
   该公司决定用更便宜的替代品替代其产品，这引起了对可持续性的担忧。
3. 3. The scientist made a cross-substitution in his experiments to see if it would work.
   科学家在他的实验中进行了交叉替代，看看是否有效。