Don't have a cow—it's no big deal.

别发火，没什么大不了。

《牛津词典》

If you went out now, Dad would have a cow.

如果你之前出去了，爸爸很有可能会非常生气。

youdao

You have a cow.

你有牛一头。

youdao

Now have made a genetic map of a cow.

VOA: special.2009.05.05

So, it's awkward to have to wait for a cow to get infected before you can vaccinate a population.

在给人们预防接种之前,你只有干等着,直到有一头奶牛感染了病毒才行

耶鲁公开课 - 生物医学工程探索课程节选

What if you're talking about a group of people that don't have any cows in their vicinity, let alone a sick cow?

万一你遇到一群人,他们附近连头奶牛都没有,更不用说受病毒感染的奶牛

耶鲁公开课 - 生物医学工程探索课程节选

"Not only does Tencent have a cash cow in its strong gaming business, but the company is also best-positioned in high-potential markets like social media and mobile Internet services, " said Jefferies analyst Cynthia Meng, who has a buy rating on Tencent's stock.

WSJ: China's Tencent Outperforms Its Western Peers

"Up until now, patent donations have been a cash cow because the IRS turned an inadvertent blind eye, " says David Martin , chief executive of M-CAM , the Virginia-based company the IRS hired to help detect abusive tax strategies relating to patents.

FORBES: Magazine Article

And if he identifies a sick cow he will have saved the cow, because the moment she has a physical sickness or a fever it's already too late.

BBC: RTLS: The technology tracking cows to make them happy