protective diffusion

例句：

1. 1. The protective diffusion of the virus is crucial for controlling its spread.
   病毒的保护扩散对于控制其传播至关重要。
2. 2.The researchers found that the protective diffusion of the virus was slowing down.
   研究人员发现，病毒的保护扩散正在减缓。
3. 3. The protective diffusion of the virus has led to a decrease in the number of cases.
   病毒的保护扩散导致了病例数量的减少。