(tòu, ㄊㄡˋ) to penetrate; thorough; penetrating; to pass through; to pierce [CE-DICT]
过
(guò, ㄍㄨㄛˋ) (experienced action marker); to cross; to go over; to pass (time); to celebrate (a holiday); to live; to get along; excessively; too-; surname Guo [CE-DICT]
质
(zhì, ㄓˋ) hostage; substance; nature; quality; Taiwan pr. zhi2 [CE-DICT]
素
(もと) (n) (1) (usu. 元) origin; source; (2) (esp. 基) base; basis; foundation; root; (3) (also 因, 原) cause; (4) (esp. 素) ingredient; material; (5) (元 only) (somebody's) side; (somebody's) location; (6) original cost (or capital, principal, etc.); (7) (plant) root; (tree) trunk; (8) (See 和歌) first section of a waka; (ctr) (9) (本 only) counter for blades of grass, tree trunks, etc., and for falcons (in falconry); (n) (10) handle (chopsticks, brush, etc.); grip; (P) [EDICT]
(す) (adj-no,n) (1) plain; unadorned; undecorated; unadulterated; au naturel; (pref) (2) (derog) (before a noun) mere; poor; (3) (before an adjective) exceedingly [EDICT]
(そ) (adj-na,n,adj-no) (1) plain, white silk; (2) {math} (See 互いに素) prime; (P) [EDICT]