2 . These days, a special “tour group” has caught people’s eyes. This group is a family of 15 wild（野生的）Asian elephants. They lived in Xishuangbanna in the south of Yunnan.

Last year, they left their home and started to move north. They visited many places in Yunnan. They walked through: mountains, forests, rivers and even city streets. They ate in the fields and slept in the wild. No one knows when the elephants will stop moving. For protecting the elephants, experts used drones（无人机）to watch them closely.

Asian elephants are usually kind. But when they are scared, they may attack（攻击）people. Experts put fences（围栏）and trucks between the elephants and people. They used tons of food like bananas and pineapples to lead the elephants to safe places.

3 . Could a robot dog help people with Alzheimer's disease (阿兹海默症) and other forms of dementia (痴呆)?

American businessman Tom Stevens thinks so. He recently presented a test version of a yellow Labrador puppy to people in a nursing home in California.

Stevens believes the robot dog, which moves its head from side to side and wags (摇) its tail, can help people with dementia. It is also easier to care for than a real dog. The robot has 16 motors to control its movements and has sensors (传感器) to answer people's voice and touching. Stevens said he came up with the idea for the robot after his mother was diagnosed with Alzheimer's in 2011. "Of the many bad days that we had early on, by far the worst was when I had to take away her dog, "Stevens said.

The robot puppy, which is called Jenny, cannot walk and is carried on a small bed. During a visit last month, at the Sage Mountain nursing home in Thousand Oaks, people suffering from dementia and other memory related illnesses put smiles on their faces while petting (爱抚) the puppy.

Jenny has visited the nursing home a number of times. "The dog is very clever, the tail wagging, responding (有反应) to them calling her name," said Caroline Gibson, a spokeswoman for the nursing home. She added that it was "really amazing" to see the nursing home's residents feel comfortable.

Stevens plans to sell its robot dogs in 2022 and it will enter a robot dog market that includes Sony's Aibo. P&S Market Research supposes that the market for personal robots may reach over $30 billion by 2022.

4 . Daniella Benitez is a 14-year-old girl. She is a new student in Cathedral Catholic High School in San Diego. She joined a non-profit organization (非营利性机构) to help people in need three years ago (以前). She helps build (建造) homes for people. "After we help build a home for people in Tijuana, she says she wants to build one home every year," says her mother, Ghada. Then Daniella gets a group of people to do the same thing with her.

Bob Williams is from Long Grove, Illinois. He makes a positive impact among people around him (对他周围的人产生积极影响). Every Saturday morning, he buys chocolate (巧克力) in a food store. Then he gives the chocolate to people he meets everywhere. "Why do I do that? It's good to know people around me. You see the same people all the time, but you never really know them. I want to change (改变) that," he says.