penetration of grease

例句：

1. 1.The oil penetrated the paper easily.
   油很容易渗透进纸里。
2. 2. The ink penetrated the paper with ease.
   墨水很容易渗透进纸里。
3. 3. The bacteria penetrated the skin and started to multiply.
   细菌开始在皮肤上繁殖，并渗透进去。