我们需要修改计划以降低成本。

We need to ___modify the plans to reduce costs.

这个项目应该被修改，以更好地满足我们的期望。

The programme should be ___modified to better meet our expectations.

科学家们正试图改良这种植物，使其对疾病更具抵抗力。

Scientists are trying to ___modify the plant to make it more resistant to disease.