source：n.来源;出处;信息来源;原始资料;起源;根源;原因；
vt.(从…)获得；
第三人称单数： sources复数： sources现在分词： sourcing过去式： sourced过去分词： sourced
例句：
We source all the meat sold in our stores from British farms.
我们商店里卖的肉均从英国农场购进。
The threat of losing their jobs is a constant source of worry to them.
丢掉工作的威胁时常使他们忧心忡忡。
Peas, beans and lentils are a good source of vegetable protein.
豌豆、豆荚和扁豆是植物蛋白质的大好来源。
Government sources denied there had been a deliberate cover-up.
政府方面否认了有故意掩饰的行为。