An average person consumes 144 pints of milk a year, but 40% of that is poured on to cereal and 60% of those people are children. But what was once advertised as nutritious is becoming unpopular.  22  Americans drink 37% less milk than they did in the 1970s. And in the UK, dairy consumption overall has fallen by a third in the past 20 years.  23  Milk is increasingly being described in a negative light. A recent blog suggested: “Maybe people are drinking less milk because it is poisonous to many of us.”  24  Lactose is the sugar found in milk and dairy products. It needs a series of complex proteins to break it down. Without enough of these proteins, the lactose is broken down by bacteria in the human body. This can cause physical pain and produce gas in the stomach. However, after we have finished breast or formula feeding, most of us don't continue producing the complex proteins in our body, which are necessary to break down the lactose. Despite the problems in digesting milk, it does provide many benefits.  25  Milk is nutritious — it contains vitamins A and D as well as protein and isn't full of calories. You can test yourself by drinking a large glass of milk. If you get sick in your stomach within the next 24 hours, you are lacking the proteins to digest milk.

一个普通人一年要消耗144品脱牛奶，但其中40%是混合谷类食物饮用的，并且其中60%是由儿童消耗的。然而，曾经被宣传为营养品的东西现在变得不受欢迎了。 22  美国人的喝奶量相比上世纪70年代减少了37%，在英国，乳制品总体消费量在过去20年里下降了三分之一。 23  越来越多的人用负面的眼光来描述牛奶。最近的一篇博客认为，人们减少喝奶，也许是因为牛奶对我们很多人都有害。 24  乳糖是乳制品中牛奶所含的糖。它需要一系列复合蛋白质来进行分解。如果没有足够的蛋白质，乳糖就会被人体内的细菌分解。这会导致身体疼痛并在胃里产生气体。然而，在经历完母乳喂养或奶粉喂养后，我们大多数人体内都不会继续产生分解乳糖所必需的复合蛋白质。尽管牛奶存在消化的问题，但它确实提供了许多好处。 25  牛奶很有营养——它富含维生素A和D以及蛋白质，而且不含热量。你可以喝一大杯牛奶来测试一下自己。如果在接下来的24小时内胃部不适，你就是因为缺乏消化牛奶的蛋白质。

22.关于美国人，这篇文章说了些什么？

A)他们喜欢喝低脂牛奶。

B)他们认为牛奶有益健康。

C)现在他们喝的牛奶量减少了。

D)他们买的牛奶比英国人多。

23.现在的美国人和英国人如何看待牛奶？

A)它不像以前人们认为的那样健康。

B)它很难长时间保鲜。

C)它使老年人受益更多。

D)它容易使人发胖。

24.为什么喝牛奶会引起一些人的疼痛？

A)他们每天喝太多品脱。

B)他们对某些矿物质很敏感。

C)他们缺乏必要的蛋白质来消化它。

D)他们吃了与牛奶不相容的食物。

25.文章提及牛奶的好处是什么？

A)病人更容易消化。

B)它提供了一些必需的营养。

C)它比其他动物产品更健康。

D)它为身体提供足够的热量。