For example, tetracycline is common on mainland China's pig farms.

比如，国大陆的养猪场普遍使用环。

This little piggy will be fed penicillin and tetracycline before it goes to market.

这只小猪在上市前要喂青霉和环。

To keep it alive in the laboratory they use a compound called tetracycline.

为了在实验室保持它的活力， 他们使用了一种环的化合物。

From the sirplane, he threw down a lot of tetracycline.

他自飞机上投掷下大量的环。

There are exceptions though; expired antibiotics in the tetracycline family can actually cause kidney damage.

不过也有例外； 环家族过期的抗生实际上会导致肾脏损害。

In this case, the stool culture can be helpful in deciding which antibiotics would be most effective against the infecting strain, and may include tetracyclines, ciprofloxacin, ofloxacin, furazolidone, or trimethoprim-sulfamethoxazole.

粪便培养可以帮助确定哪种抗生对感染菌株最有效，可用的药物包括环、环丙沙星、氧氟沙星、呋喃唑酮或甲氧苄啶-磺胺甲恶唑。