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.

    Do you think you're green? You're a totally modern citizen, aren't you? You keep your bottles and take them to the bottle bank. You have a black bin and a green bin, one for general waste and one for recyclable waste. Your car uses lead—free petrol. You use the same plastic bag every time you go to the supermarket. Maybe you even cycle to work from time to time. You are playing your part; you are green and environment—friendly. Well, I've got news for you:

    YOU ARE NOT DOING ENOUGH!

    If you don't believe me, look at these facts. Trust me, they're from a BBC website.

    On average every person in the UK throws away their own body weight in rubbish every seven weeks.

    Every year, the average dustbin contains enough unused energy for 500 hot baths, 3,500 hot showers or 5,000 hours of television.

    Every UK household produces over one tonne of rubbish every year.

    If all the aluminium drink cans sold in the UK were recycled, there would be 14 million fewer full dustbins per year.

    Just one recycled aluminium can saves enough energy to run a television for three hours!

    At Christmas over 83 square kilometres of wrapping paper is thrown in the bin.

    Almost three billion nappies (used for baby) are thrown away in the UK every year. 90% of these are buried and take hundreds of years to disappear.

    Have I made you believe that you need to do more? No? OK, here are one or two more facts.

    Recycling just one plastic bottle saves enough energy to power a light bulb for six hours.

    Collecting dustbins and cleaning streets costs ￡1. 6 billion per year.

    Surely you must believe me now. You need to do more. The good news is that there is some— thing else you can do.

    It is a question that has confused parents for many years: why do children refuse to eat greens?

    Now, two American experts believe they have the answer.

    After studying dozens of babies as they played with various objects, the researchers noted that they were far more unwilling to touch plants than other things. They believe this is because evolution (生物进化) has biologically made children be wary of plants.

    Due to susceptibility (敏感性) to illness or injury in the early years of life, the body has designed an inner defence mechanism (内部保护机制) that limits a child' s contact with plants, they think. The researchers believe this is why children turn their noses up when faced with a plate of broad beans.

    The findings are published in a paper by Dr Annie E Wertz and Dr Karen Wynn, both psychologists at Yale University.

    They wrote, "Throughout human evolution... plants have been important in human's life. Yet, for all of these benefits, plants have always caused very real dangers."

    "Plants produce toxins (毒素) as defences that can be harmful, or even deadly. Some plants also produce physical defences, such as thorns（荆棘）can damage tissues (组织) and cause effects over the whole body."

    They added, "We predicted that babies may have behavioural strategies that reduce dangers caused by plants."

    To test their theory, the researchers studied how children aged eight to 18 months old reacted when presented with a variety of objects. It took much longer for children to grab plants; objects that were pretended to look like plants also caused a slow response time.

    For parents attempting to spoon some peas into the mouth of their child, this finding should come as welcome relief.

    Height is just one of the thousands of features that your genes(基因) decide. In fact, because you have two parents, your genes provide you a height that usually lands somewhere between the height of each parent. If both your parents are tall, then most probably you will be tall, too. But if you have questions about how tall you're going to be, ask your doctor if he or she can help you find it out.

    But genes don't decide everything. For example, eating an unhealthy diet can keep you from growing to your full potential(潜力). Getting plenty of sleep and enough exercise will help you grow to the expected height.

    No doubt you're wondering how fast you should grow. There's no perfect or right answer. Generally speaking, kids grow about two inches(six centimeters) a year between age 3 and the time when they start puberty(青春期).

    Your doctor will know how your growth has been going over the years, how you've been growing up to this point, and what other changes your body may be going through.

    Don't be scared if you seem to have grown a lot in a very short time. Everyone has a growth spurt(高峰) during puberty. The age for starting puberty is about 10 for girls and about 11 for boys. But it can be earlier or later-between 7 and 13 for girls and between 9 and 15 for boys.

    You'll usually begin to notice that you're growing faster about a year or so after your body starts to show the first changes of puberty.