If you visit the animal shelter in Salinas, California, you'll see huge wood cutouts(剪下的图形) of a dog and a cat. These signs were placed in front of the building to catch people's attention. The supersized cut outs make people curious and encourage them to visit the shelter— and maybe even adopt(收养) a pet. Each year, the Salinas shelter takes in around 2,000 dogs and 2,000 cats. The animals are either strays or are dropped off by people who couldn't take care of them. Of the 4,000 animals, some of them are finally adopted into new homes. Some animals are moved to other shelters. And, unluckily, some cannot be saved because they are too sick or are considered dangerous.   

   Animal shelters provide food, medicine, and a safe place for animals to sleep. But they are not ideal homes. The shelters are loud, and the animals stay in small cages. The people who work at shelters do their best to care for the animals, but the animals do not always get the attention or exercise they need.  

   To prevent so many animals from becoming homeless, pet owners should take care of their pets. One of the best ways to care for pets is to spray or neuter them. This surgery prevents cats and dogs from having more babies. And that reduces the number of homeless animals that end up in shelters.

Radio, telephone and TV are widely used in the world. When you turn on the radio, you can listen. But when you use telephone, not only can you listen to others but also you can chat with them, however, you can't see anything at all. TV is much better than both of them. People can watch TV and listen to it, but they can't take part in what they see.

    Today, some people are using a type of telephone called vision-phone（可视电话）. With it, two people who are talking can see each other. It is better than radio, telephone or TV.

    Vision-phones can be of great use when you have something to show the person whom you are calling. It will be helpful in people's life. Some day you may be able to call up a library and ask to read a book on your vision-phone. You may be able to do some shopping too. Perhaps in the future, people will use vision-phone.

A

    In recent years, there have been many breakthroughs in the AI (人工智能) field. Here, let us see four of the most interesting developments in AI in 2017.

    North American black bears are shy animals. They are fearful by nature, and will usually run away if they see or hear people. Because of this, it can be difficult for scientists to learn about these animals.

    In order to study black bears, researchers from New Jersey, the US, catch bears and use drugs to help them go to sleep. Researchers then work out the size and the weight of the bears, take blood, to test for diseases, remove a tooth and take it to the lab to find out its age. From these studies, researchers want to find out how many bears live in New Jersey, how long they live, and how many babies they produce.

    But in Minnesota, the US, researchers study bears that are completely awake. The bears know the researchers' voices and they are not afraid of the research team. With the help of a few grapes to keep the bears busy, researchers can touch them to check their hearts, look at their teeth, and do other jobs. Researchers can also walk or sit with bears for hours and make videos to learn about their everyday lives."

    In both places, the main purpose is the same—to make sure there is a healthy population of black bears. But the research methods and the kinds of information that researchers are able to collect are quite different.