How Milk Goes Down Around the World 牛奶，你适合喝吗？

如您想获得本篇文章的英文文稿、翻译及讲解资料，请加我的微信好友“JEworks”，或是添加我的微信公众号“为语筹谋”，输入关键字“牛奶”。在那里，我还会将定期推送些免费的写作指导及口语表达等课程。 英文原稿 Got milk? If so, you also may get stomach pain after you drink a glass of it. That’s because most of the world’s adults — an estimated 68 percent — aren’t able to digest it. Their condition is commonly called lactose intolerance. It stems from a lack of lactase, an enzyme that breaks down the milk sugar lactose. Lactase is present in young children but weakens in most people after weaning, according to evolutionary geneticists. The enzyme continues to be produced, extending the ability to digest dairy, only in smaller populations of adults around the globe. Though what sparkled the digestion divide is uncertain, one pattern may shed light: Milk tolerance in adults is more common in regions with a history of raising dairy mammals, such as cattle, goats, and sheep. —— end ——