▲你的句子中：big business 前面之所以既没有冠词，也没有用复数形式，是因为它在此是表示统称意义的“大企业”，是一个不可数名词。

▲big business的两层意思

big business 表示“大企业”有两层用法：一是表示个体意义的大企业，二是表示笼统意义的大企业——表示前者的意思时，它是可数的；表示后者的意思时，它是不可数的。比较：

1. 可数用法（表示具体意义）

Many big businesses start from small beginnings. 许多大企业都是从小企业起步的。

First of all, there are not many of them, and secondly, they have little money and, thirdly, they have few big businesses. 首先，他们人数不多；第二，他们钱很少；第三，他们没有几家大企业。

2. 不可数用法（表示笼统意义）

Big business and politics were inseparable bedfellows. 大企业和政治是一对不可分割的盟友。

Most of their economic policies serve the interests of big business. 他们的经济政策多半符合大企业的利益。

▲关于固定搭配big business

big business 作为固定搭配的用法在词典中可以查到，它有两个意思，均为不可数名词：

1.[U]（统称）大公司，大企业，大财团

links between politics and big business 政治和大企业之间的联系

The party has loosened its links with big business. 这个政党与大企业的关系疏远了。

The party receives most of its financial support from big business. 这个政党主要从大财团那里获得财力支持。

Sometimes small firms can outdo big business when it comes to customer care. 在顾客服务方面，有时小企业可能优于大企业。

Big business will never let petty nationalism get in the way of a good deal. 大企业永远不会让狭隘的民族主义妨碍它们做大好的买卖。

2.[U]大买卖，大生意，赚大钱

Dieting has become big business. 节食减肥现在成了大生意。

Sport has become big business. 体育已经成了一大产业。

Britain’s railways are big business. 英国的铁路业务规模巨大。

Health and fitness have become big business. 保健已经成为大生意。

Health clubs are big business these days. 如今健身俱乐部是很赚钱的。

The craze for health foods has become big business. 健康食品热创造了巨大的商机。

With all the diet-food and books on the market, slimming is big business these days. 市场上所有那些减肥食品和书籍都显示当下减肥非常流行。