List three public corporations and the services they provide.

1. Apple Inc. - Apple is a technology company that designs, manufactures, and sells consumer electronics, software, and online services. Some of their popular products and services include the iPhone, iPad, Mac computers, and the App Store.

2. Walmart Inc. - Walmart is a retail corporation that operates a chain of hypermarkets, discount department stores, and grocery stores. They provide a wide range of products including groceries, clothing, electronics, and household goods.

3. Exxon Mobil Corporation - Exxon Mobil is an energy corporation that explores for, produces, and sells crude oil and natural gas. They also manufacture and market petrochemicals and other petroleum products. Exxon Mobil is one of the largest publicly traded companies in the world.

1. Amazon: E-commerce, cloud computing, digital streaming
2. Google: Search engine, advertising, cloud computing
3. Walmart: Retail stores, e-commerce, financial services