Robots are smart. With their computer brains, they help people work in dangerous places or do difficult jobs. Some robots do regular jobs.Bobby, the mail carrier, brings mail to a large office building in Washington, D.C. He is one of 250 mail carriers in the United States.

Mr. Leachim, who weighs two hundred pounds and is six feet tall, has some advantages as a teacher. One is that he does not forget details. He knows each child’s name, the parents’ names and what each child knows and needs to know. In addition, he knows each child’s pets and hobbies. Mr. Leachim does not make mistakes. Each child goes and tells him his or her name, then dials an identification (身份证明) number. His computer brain puts the child’s voice and number together. He identifies the child with no mistakes. Then he starts the lesson.

Another advantage is that Mr. Leachim is flexible. If the children need more time to do their lessons they can move switches. In this way they can repeat Mr. Leachim’s lesson over and over again. When the children do a good job he tells them something interesting about their hobbies. At the end of the lesson the children switch Mr. Leachim off.

The kitchen inventions throughout history have paved the way for safer meals. However, do you know how the following kitchen aids came about?

The Oven

Historians owe the invention of the first ovens to ancient Egyptians. The earliest ones were taller and made of baked clay. Inside, they were divided into separate upper and lower chambers(室). The oven was heated by burning wood in the lower chamber. Food to be baked was put into the upper chamber through a hole at the top of the oven.

The barrel

According to historical records from the first century, the first wooden barrels were produced by people who lived in the Alps, Europe’s highest mountains. For centuries, such barrels have been used to store and transport dry goods as well as wine and beer. Because of their curved(弯曲的) sides and round tops and bottoms, barrels can be rolled, which makes them easier than boxes to handle. Today, metal barrels are widely used to store oil and other liquids.

The egg carton

Back in 1911, an argument in British Columbia, Canada, led to a useful invention. Eggs shipped by a local farmer to a hotel owner often arrived broken, and each blamed the other for the damage. To solve the problem, Canadian newspaperman Joseph Coyle invented a paper carton with small and hollow(空的) spaces that cushioned the eggs and kept them separated. Coyle’s invention was so successful that we still use it today.

The knife

Many believe the knife is mankind’s oldest tool, with the earliest forms made from flint(燧石) or a glass­like rock and then from metal around 2500 BC. Through the years, the cutting device evolved into the handy tool we use today.

While we take these inventions for granted now, our lives would be very different without these kitchen aids.

A new product from Microsoft Corporation can do just that for people who have trouble seeing. They may be blind or visually challenged. The product, an app, is called Seeing AI. "AI" is short for artificial intelligence, a term for computers with an ability to think and learn like human beings.

Seeing AI is currently available for free for Apple's iPhone and iPad in Canada, Hong Kong, India, New Zealand, Singapore and the USA. It has four Channels: Short Text, Document, Product, and Person. After you download it, the app will show video directions for each channel. And the app uses both a camera and artificial intelligence to identify places, objects and people (even the emotions of people).

People can use Seeing AI to learn words in English. With the app open, you can point your iPhone or iPad at any object and it will say what the object is. People can also use the app when going to a store or supermarket. It can read product bar codes(条形码) so users will know whether a can is filled with fruit or dog food. In addition, at restaurants, diners can use it to hear a list of drinks and other menu offerings. It can recognize both food choices and prices. And in the near future, it will be able to identify banknotes so people know whether they are holding a bill that is worth $100 or $1.

However, as a new app, seeing AI will not be correct 100% of the time. For example, just because someone is smiling does not necessarily mean they are happy. The app recognizes text, but not handwriting yet. That feature may be available in the future. Also, Seeing AI needs to be connected to the Internet to work.