translation.en: So we've all heard of MRIs. MRIs use magnetic fields and radio waves and they take snapshots of your brain or your knee or your stomach, grayscale images that are frozen in time.
translation.zh: 我们都听说过磁共振成像 MRIs利用磁场和无线电波来给你的大脑， 或膝盖，胃等“拍照” 它会把拍摄瞬间的活动以灰阶图记录下来