What is protein? 什么是蛋白质？

It is one of the most important nutrients, animals need. 它是一种动物所需的最重要的营养物质。

People really need a lot of protein. 人们需要大量的蛋白质。

Protein helps a person to grow cells in muscles. 蛋白质有助于人们肌肉内细胞的生长。

Without protein, we cannot stay healthy. 没有蛋白质，我们就不能保持健康。

Eating protein is important. 食用蛋白质很重要。

However, we should not eat too much protein. 然而，我们不应该吃得太多。

Do you know why? 你知道为什么吗？

Because our bodies cannot store protein. 因为我们人体不能储存蛋白质。

Instead, our bodies change a new protein into fat. 相反，我们的身体会把新的蛋白质转化成脂肪。

Therefore, we must have a balanced diet. 因此，我们要有均衡的饮食。

Where do you think we can get protein? 我们从哪儿能获取蛋白质？

We can get protein from meat, fish and beans. 我们可以从肉类、鱼类和豆类中获取蛋白质。

They're major sources of  protein. 它们是蛋白质的主要来源。