Vocabulary consisting only from characters you are able to read
往々にして
ouounishite
sometimes, occasionally, now and then, from time to timemix
最適
saiteki
optimum, the most suitablemix
効力
kouryoku
effect, efficacy, validity, potencymix
金庫
kinko
safe/vault/treasury/provider of funds; safe/vault/treasury/provider of funds/(P)mix
利く
kiku
(1)to be effective, to show effect, (2)to do its work, to carry out its function well, (3)to be possible to use godan, verb, vintrans