attenuated virus

例句：

1. 1. The virus has been attenuated to make it less dangerous.
   该病毒已被减弱，使其危险性降低。
2. 2. Thevaccine was designed to attenuatethe virus.
   疫苗被设计来减弱病毒。
3. 3.The research team found a way toattenuate the virus without harminghumans.
   研究小组找到了一种方法来减弱病毒而不伤害人类。