过硬

to have perfect mastery of sth / to be up to the mark

surname Guo

to cross / to go over / to pass (time) / to celebrate (a holiday) / to live / to get along / excessively / too-

(experienced action marker)

hard / stiff / strong / firm / resolutely / doggedly / good (quality) / able (person) / (of food) filling / substantial