replacement mutant

例句：

1. 1. The new drug has been shown to be a replacement for the old one in treating cancer.
   新药已被证明是治疗癌症的旧药的替代品。
2. 2.The research team discovered a replacement mutant that could potentially cure the disease.
   研究小组发现了一种潜在的替代突变体，有望治愈这种疾病。
3. 3. The scientists are working on developing a replacement mutant for the antibiotic resistance gene.
   科学家们正在努力开发一种替代抗药基因的突变体。