phrasal verbphr v informalEFFECTIVEto have great confidence in how good or effective something is 极其信赖
He swears by vitamin C pills.
他很相信维生素 C 片的效用。
Examples from the Corpus
swear by • The mother-goddess swore by a necklace of blue stones.• A: Some cooks say that basting does nothing to ensuremoistmeat; others swear by it.• There is no medicalproof that taking VitaminB6 helps, but some of his patients swear by it.• Other friends swore by Jenny Craig because it was so convenient.• The parson would swear byJupiter to show he's a public school man but these old women would have him.• The Proconsul offers him a last-minutereprieve, however, if he will repent and swear by the genius of Caesar.• At the Morse School, principal James Coady and his teachers swear by the results.• Some swear by the techniques of Life CycleAssessment, whilst others see it as a crudesubstitute for sound judgment.