-----------------------------------
@ 中， なか
1. inside, interior
2. among, within
3. middle, center, centre
4. during, while, middle, midst, amid
5. interval, gap
6. mean, average
7. second (of three, e.g. sons, volumes), middle
8. medium grade, medium quality
9. red-light district
内，内部；中，其中；中，中心；当……，……时，……期间；中等