We tend to meet up for lunch once a week.我们往往每周共进一次午餐。Lung cells die and are replaced about once a week.肺细胞约每周新老更替一次。Meat was available once a week if at all.就算有肉，也是每周才吃一次。...
The treatment involves the placement of twenty-two electrodes in the inner ear.这一治疗需要在内耳放置22个电极。The electrodes are immersed in liquid.电极浸没在液体中。Every transistor has at least three electrodes.每个晶体管至少有三个电极....