(zài, ㄗㄞˋ) (located) at; (to be) in; to exist; in the middle of doing sth; (indicating an action in progress) [CE-DICT]
填
(tián, ㄊㄧㄢˊ) to fill in [CE-DICT]
补
(bǔ, ㄅㄨˇ) to repair; to patch; to mend; to make up for; to fill (a vacancy); to supplement [CE-DICT]
先
(せん) (adj-no,n) (1) former; previous; old; (n) (2) first move (in go, shogi, etc.); opening move [EDICT]
(さき) (n,adj-no,n-suf,pref) (1) previous; prior; former; some time ago; preceding; (2) point (e.g. pencil); tip; end; nozzle; (3) head (of a line); front; (4) ahead; the other side; (5) the future; hereafter; (6) destination; (7) the other party; (P) [EDICT]
(xiān, ㄒㄧㄢ) early; prior; former; in advance; first [CE-DICT]