尿液是无菌的。Urine is sterile.手术室应该是个无菌的环境.An operating theatre should be a sterile environment.生长中的胎儿是处于无菌的羊水中,羊水能避免碰撞和病菌.A developing baby floats in sterile amniotic fluid , protected from bumps — and bugs....
他把鞋袜一扒, 光着脚趟水.Taking off his shoes and socks , he waded across barefoot.桥被冲走了,我们不得不趟水过溪.The bridge was washed away and we had to wade the stream.我们到浅水处去趟水.We went for a wade in the shallows....