yǒu jī hé chéng / zhōng / kē xué jiā / cháng / tōng guò / yǐn rù / bù tóng / qǔ dài jī / lái / gǎi biàn / yào wù / huó xìng

有机合成中，科学家常通过引入不同取代基来改变药物活性。

In organic synthesis, scientists often change drug activity by introducing different substituents.