concentration

n.专注，专心；集中；浓缩

comradely, comradeship, con, con man, concatenate, concatenation, concave, concavity, conceal, concealment, concede, conceit, conceited, conceitedly, conceivable, conceivably, conceive, concentrate, concentrate on, concentrated, concentric, concept, conception, conceptive, conceptual, concern, concerned, concernedly, concerning, concert, concert grand, concert-goer, concert-master, concerted, concertina, concerto, concess, concession, concessionaire, concessionary,