There is a popular belief that goldfish only have a three-second memory. But a 15-year-old schoolboy from Adelaide has just finished an experiment（实验）to tell us that it is not true. He shows everybody that the goldfish is smarter than we think.

    “I don't believe that they had a three-second memory because animals need their memory, so they build up over time a knowledge of where the food is,” said Roy Stokes, a student at the Australian Science and Mathematics School.

    He did the experiment in small tank（鱼缸）of goldfish. “I decided to get a bit of red Logo and just feed them next to that. Every day I'd put it in and spread food around it.” He said.

    “At first they were a bit scared of it, but by the end of the three weeks, they were actually almost coming before I put the food in.”

    After leaving the fish alone for a week, Rory placed the red Logo block in the tank again.

    “They remembered perfectly well,” he said.

    “They actually had a time faster than the average of the three feeds before I left.”

    The goldfish showed that not only could they store information, they also had the ability to get it back as a later date.

    Culum Brown, a research fellow at Sydney's Macquarie University, has studied fish behavior for more than ten years.

    He says his studies of Australian native fish show fish were intelligent creatures that know how to avoid enemies and catch food like any other animal.

    “The thing that I really liked about Rory's experiment is he not only got that classical conditioning going but the fact that he could get them next just to that specific coloured market. I thought it was really good.” He said.

    Sheridan is a town in Indiana, USA. There are lots of trees near the public schools in the town. Their leaves turn sunlight into energy（能量）.

    In Sheridan, the sun not just provides energy for plants. It keeps schools running, too. The schools use solar panels（太阳能电池板） to turn sunlight into energy.

    The science behind solar energy is not new. But Sheridan Community Schools is the first school district(学区) in Indiana to be completely solar-powered. The district finished putting in solar panels for all three of its schools in 2016. Some of the panels can turn to follow the sun across the sky.

    In 2008, fewer than 1. 000 schools used solar power. By 2014, there were 3, 727 schools with solar panels in the USA. These numbers come from a report by the Solar Foundation. Roxie Brown, a program director there said that the number of schools with solar panels has continued to go up since 2014.

    Solar energy has some advantages over other energy sources(来源). Sunlight is a renewable source, which means it won't run out. Solar panels don't harm the environment. Also, sunlight is free. So by using solar power, schools can save money on energy costs.

    Brown thinks more schools should run on solar energy. "The sun is Earth s energy source," she says. "We're trying to make it the energy source for our houses cars and schools, too."

    But using solar energy isn't always easy. Solar panels can be expensive to put in. The panels also take up space. But for many schools, going solar is worth it.

    Every time when I look at the moon, I wish I could go there. Do you wish you could fly to the moon in a spaceship one day?

For hundreds of years, men have wanted to travel to the moon. When they looked at the moon, they asked many questions. Was the moon hot or cold? Were there any plants or other living things there? There were many, many other questions.

    We know much about the moon now. Scientists have studied the moon for many years and have found out many facts. So far, some men have got to the moon on spaceships.

    Scientists have found that the moon is much smaller than the earth. It is about one quarter the size of the earth. It is traveling round the earth all the time. There are not any plants or other living things on the moon, because there is no air or water there.

    Days and nights on the moon are very long. One day on the moon is as long as two weeks on the earth. One night is also as long as two weeks on the earth. In the day the moon is very hot. At night it is very cold. The moon is much hotter and much colder than the earth.

    There is another surprising thing. On the moon things are not as heavy as they are on the earth. Isn't that interesting? Perhaps one day we can all travel to the moon. It must be great fun.