Identify and correct ten mistakes in the following passage

VI.  Identify and correct ten mistakes in the following passage.

As more things are make to be sold and more people have services to sell, advertising grows. Today it is one of the bigger businesses. Every year people spend billion of dollars on advertising

Advertising help sell more things to more people. This in turn makes it possible produce more things to sell. Sometimes it even helps make things cost less. In the beginning, for example, radios costed much more than they do today so they were turned out slowly and expensive by hand. Yet, advertising made more people want radios. When manufacturer began making them by the thousands, they found quickly and cheaper ways of doing the job. Because advertising encourages us to buy and produces more things, it is sometimes called the spark of the business world