carriers
n. 运送者，媒介物；运输公司（carrier 复数）
例句
Regional carriers get paid for calls that pass through their switches.
地方运营商向那些通过其转接台的电话收费。
《柯林斯英汉双解大词典》
Their cost structure is such that they just can't compete with the low-cost carriers.
他们的成本结构是这样的以致于他们就是没法与那些低成本的运输公司竞争。
Primary groups, then, serve both as carriers of social norms and as enforcers of them.
因此，初级群体既是社会规范的载体，又是社会规范的执行者。
