For centuries, elephants have played a big role in the world's economies, culture and religion. The African elephant used to be found all over Africa and the Asian elephant moved from Syria to China to Indonesia. Nowadays, elephants are found in small groups in the south of the Sahara Desert and scarcely in Southeast Asia, Sri Lanka and India.

    In the early twentieth century, there were close to ten million elephants, and now the elephant number is as low as 252,000 and expected to drop down to 160,000 by 2025. Between 2007 and 2014, the elephant population fell by at least 30%, or 144,000 elephants. As researchers have traveled over the African plains, they only spotted one herd of 36 elephants in an area like the size of Mexico. It is clear that these gentle mammals are disappearing right before our eyes.

    There are many reasons why the elephant population has been decreasing, one of which is their habitat. Humans are competing with elephants for living space, and as more and more humans clear the land that is being used by elephants, the elephants have less space. Elephant hunting or "poaching" has been a major factor for the disappearance of this species, and they are killed only for their valuable ivory tusks. Although the trade of tusks is illegal, it is still a common practice in many places.

    Often, all the local people living among elephants would be farmers, and found that they could make more money by selling the tusks of one elephant, than doing manual labor for twelve years. That alone makes it really hard to prevent them from killing the elephants.

    Some places such as Botswana, have put in extra effort to protect their wildlife from poachers by founding their Botswana Defense Force, which is made up of around 700 specially-trained soldiers that are stationed in 40 different areas. You may feel worried about the present situations elephants are in, but there are ways to help. To find out how you can help elephant conservation, adopt an elephant, or donate, click here.

    When you go to the doctor, you like to come away with a prescription．It makes you feel better to know you will get some medicine. But the doctor knows that medicine is not always needed. Sometimes all a sick person needs is some reassurance that all will be well. In such cases the doctor may prescribe a placebo.

    A placebo is a sugar pill, a harmless shot, or ail empty capsule. Even though they have no medicine in them, these things seem to make people well. The patient thinks it is medicine and begins to get better. How does this happen?

    The study of the placebo opens up new knowledge about the way the human body can heal itself. It is as if there was a doctor in each of us. The doctor will heal the body for us if we let it. But it is not yet known just how the placebo works to heal the body. Some people say it works because the human mind fools itself. These people say that if the mind is fooled into thinking it got medicine, then it will act as if it did, and the body will feel better.

    Placebos do not always work. The success of this treatment seems to rest a lot with the relationship between the patient and the doctor. If the patient has a lot of trust in the doctor and if the doctor really wants to help the patient, then the placebo is more likely to work. So in a way, the doctor is the most powerful placebo of all.

    A placebo can also have bad effects. If patients expect a bad reaction to medicine, then they will also show a bad reaction to the placebo. This would seem to show that a lot of how you react to medicine is in your mind rather than in your body. Some doctors still think that if the placebo can have bad effects it should never be used. They think there is still not enough known about it.

    The strange power of the placebo does seem to suggest that the human mind is stronger than we think it is. There are people who say you can heal your body by using your mind. And the interesting thing is that even people who swear this is not possible have been healed by a placebo．

    Recently I started discovering one thing which amazes me so much: how perfect everything is in the world we are living in! Just look, all day long we are busy working and just when we get tired, the night comes in, so we may sleep and relax. One day we may enjoy the bright sun and another day, when we get tired of the sun, the rain pours down.

    A few months ago I was so happy with my life. Later, I got tired from the happiness. I wished I would have some trial to strengthen my character and learn something new about life. I got what I wanted. Shortly after I got severe angina (心绞痛), so I had to stay home for several weeks. During this period I had time to rethink my life and discover myself. The lessons were terrific, but I felt grateful for this time.

    Another example: I have a friend, who primarily thinks about having fun. Once I thought why we get along well with each other and what in me attracts her. A couple of days ago I found the answer. I like calmness and silence. She likes noise and agitation (热闹). We attract each other just to balance ourselves, in other words, to give some drive to me and some calmness to her!

    So remember that the universe is so wise that it will try to balance you. As for me, this is perfect because extremes create suffering: too much food – too little food, too cold – too hot, too much fun – too little fun.

    Green tree ants are important builders in the rainforest. They're like the worker bees of the ant world. The native forest of Thala Beach Nature Reserve is the natural home of these insects.

    They climb all over the tree that contains their nest and protect it from enemies with great fierceness. The ants are often in the fruiting trees of Tropical North Queensland. When an animal tries to help themselves to some tasty fruit, they find themselves attacked by a powerful, frightening army of green tree ants! Their bite is not very painful but many ants attacking at the same time can be extremely uncomfortable.

    The nests are large and constructed by sticking the leaves at the end of branches together to create a home looking roughly like a globe. Most of the nest construction and weaving is conducted at night. A mature colony of green tree ants can hold as many as 100,000 to 500,000 workers and may include as many as 12 trees and contain as any as 150 nests. Green tree ant colonies have one queen and a colony can live up to eight years.

    However, the ants are so busy that they fail to spot a dishonest figure. There is a spider called the Salticid spider, or the jumping spider, as they are sometimes referred to, which has excellent eyesight and is only active during daylight, weaving a protective covering of silk to spend the night in. Interestingly, the Salticid spider does not look like a green tree ant. Instead, it chemically copies green tree ants' smell. Effectively pretending to be an ant, it goes into the green tree ants' nest, enters the nursery and feasts on their babies. Green tree ants don't have good eyesight and smell everything with their antennae (two long thin parts on an ant's head). Therefore, the ants think the spider is another ant and ignore its presence within the nest.

    Next time, as you wander around Thala's native forest, keep an eye out for these busy little creatures. Look up into the trees and you'll likely spot their nests.

    There are many places to go on safari in Africa, but riding a horse through the flooded waters of Botswana's Okavango Delta must rank as one of the world's most exciting wildlife journeys.

    Several safari camps operate as the base for this adventure, providing unique rides twice a day to explore deep into the delta. The camps have excellent horses, professional guides and lots of support workers. They have a reputation for providing a great riding experience.

    The morning ride, when the guides take you to beautiful, shallow lakes full of water lilies, tends to be more active. It is unlike any other riding experience. With rainbows forming in the splashing water around you and the sound of huge drops of water bouncing off your body and face. It is truly exciting. You are very likely to come across large wild animals, too. On horseback it is possible to get quite close to elephants, giraffes and many other animals. The sense of excitement and tension levels rise suddenly though, as does your heart rate, as you move closer to them.

    In the evening, rides are usually at a more relaxed and unhurried pace. With golden light streaming across the grassy delta and the animals coming out to eat and drink. Sedate though they are, rides at this time of day are still very impressive. As the sun's rays pass through the dust kicked up by the horses, the romance of Africa comes to life.

    Back at the camp you can kick off your boots and enjoy excellent food and wine. Looking back on your day, you will find it hard to deny that a horseback Safari is as close as you will ever come to answering the call of the wild.

Students from Oceanside High School in Rockland will be able to sleep in a little longer from this autumn.

Regional School Unit 13 Superintendent (负责人) Lew Collins said during the school's Thursday night meeting that the schedule (时间表) for the schools will be changed. Oceanside East and West will start a half hour later, at 8 a.m. for their new school year.

Research has shown that teenagers' brains are often not fully awake at 6:30 a.m. Collins said the schedule, which is used to get students to school for classes that begin at 7:30 a.m., calls for some to get on buses before 6 a.m. to get to school on time. Teachers are having meetings at 6:40 a.m., which is too early, he thinks.

Collins visited the high schools in Rockland and asked students when they would like classes to begin. Most of them said 8:00 a.m. "I was surprised. I thought they would have said 9:00 or 10:00," he said.

The National Sleep Foundation says on its website that teenagers' biological clocks (生物钟) are designed to stay up later and get up later. The Foundation called for schools to change their schedules, which means a later start as well for elementary students (小学生).

We do not have enough buses to run, since all the high school and elementary school buses run almost at the same time, Collins said. He suggested, "We should buy six more buses and get six more drivers to keep the new schedule working."

Elementary school classes in Rockland now start at 8:30 a.m., but will be moved to 8:45 a.m., starting in the autumn. "I know this is a problem for working parents, but we will see what we can come up with," said Jane Brown, a teacher at Bardonia Elementary School. "Anyway, I believe if students get more sleep they'll be more ready to learn when classes start," she added.