KEY: Sound \v.\
SYN: Probe, gauge, investigate.
ANT: Overlook, disregard, misexamine, misinvestigate.
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KEY: Sour.
SYN: Tart, rancid, coagulated, turned, harsh, crabbed, austere, morose, pungent, crusty, acid, churlish, bitter, acetous, acrimonious, peevish.
ANT: Sweet, wholesome, untainted, mellow, genial, kindly.
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KEY: Source.
SYN: Rise, origin, spring, fount, fountain, cause, commencement, beginning.