Great inventions change the world. They help people live a better life. The following (be) three of the most important inventions in history.

    The wheel may be the greatest invention in history. Travelling became faster and (comfortable) after its invention. Several thousand years ago, people started to use wheels on carriages. In  early 19^th century, the first trains began to carry passengers. the wheel, we would not have these inventions.

One of the first (practice) telephones was invented by Alexander Graham Bell in1876. Since then, people have been able to speak to each other over long distances. Today (million) of people across the world own mobile phones. They allow people (keep) in touch with each other anytime , anywhere.

    Thomas Edison developed the first useful light bulb in 1879. With light bulbs, people can do as many things in the evenings  they can in the daytime. Can you imagine (live) a life without (they)?