Machu Picchu is an unusual site in Peru and one of the most mysterious wonders of the world. Built at almost 10,000 feet on the top of an Andean mountain, the Incas built hundreds of structures made of stone. A large number of Machu Picchu's surrounding structures date back to the early 13th century, but it was considered a chief sacred site far before then. The Inca people changed the large site into a very small but wonderful city, completely self-sufficient and hidden from below. Agricultural terraces (梯田) surrounded the entire city, fed by natural spring water, supporting the entire population.

Inca Trail

    The trail is one of the most famous in the world and regarded as one of the best. It covers only 26 miles, combining cloud forest, green mountain scenery, forest, and plenty of tunnels, paving stones, and ruins. The four-day hike begins slowly but quickly changes into a difficult journey suitable for those in excellent shape. The trail winds through the Andes, leading alongside and through ruins. Though independent hiking was once permitted, now it must be done with a guide.

Funerary Rock

    It is believed that the Funerary Rock at Machu Picchu was used as a place to prepare Inca nobles for preservation, or mummifying (做成木乃伊), a common habit among the tribe. Nobles would be laid out to be mummified by the hot sun and freezing cold nights after their organs were removed. The rock is also famous as a spot from which a view of the city is afforded.

Temple of the Sun

    Within the city's castle, deep within Machu Picchu, is the Temple of the Sun, accessed only by the Emperor and

    Inca priests. It means the Inca's advanced knowledge of religion, weather, and nature, showing the great extent

    Incas went to adapt to and learn about nature. Still unbroken, the temple was built to honor the god Inti, who is exactly the sun. The temple was effectively protected. It was also a very important scientific center, built in half-moon shape with openings facing north and east. The windows' shadows in the center of the temple helped see the start of winter solstice (至日), showing farming season.

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    Most animals have little connection with animals of a different kind, unless they hunt them for food. Sometimes, however, two kinds of animals come together in a partnership (伙伴关系) which is good for both of them. You may have noticed some birds sitting on the backs of sheep. This is not because they want a ride, but because they find easy food in the parasites (寄生虫) on sheep. The sheep allow the birds to do so because they remove the cause of discomfort. So although they can manage without each other, they do better together.

    Sometimes an animal has a plant partner. The relationship develops until the two partners cannot manage without each other. This is so in the corals(珊瑚) of the sea. In their skins they have tiny plants which act as “dustmen”, taking some of the waste products from the coral and giving in return oxygen which the animal needs to breathe. If the plants are killed, or are even prevented from receiving light so that they cannot live normally, the corals will die.

    “Soon, you're going to have to move out!” cried my neighbor upon seeing the largest tomato plant known to mankind, or at least known in my neighborhood.

    One tiny 9-inch plant, bought for $1.25 in the spring, has already taken over much of my rose bed, covering much of other plants, and is well on its way to the front door.

    Roses require a good deal of care, and if it weren't for the pleasure they give, it wouldn't be worth the work. As it is, I have a garden full of sweet-smelling roses for most of the year. bushes must be pruned(剪枝) in early spring, leaving ugly woody branches until the new growth appears a few weeks later. It was the space available(可用的) in the garden that led me into planting just one little tomato plant. A big mistake.

    Soil conditions made just perfect for roses turn out to be even more perfect for tomatoes. The daily watering coupled with full sun and regular fertilizing(施肥) have turned the little plant into a tall bush. The cage I placed around it as the plant grew has long since disappeared under the thick leaves.

    Now the task I face in harvesting the fruit is twofold; First, I have to find the red ones among the leaves, which means I almost have to stand on my head, and once found I have to reach down and under, pick the tomatoes and withdraw(缩回) my full fist without dropping the prize so dearly won. I found two full-blown white roses completely hidden as I picked tomatoes in June, but they were weak and the leaves already yellow for lack of light.

    Here I am faced with a painful small decision: To tear up a wonderful and productive tomato plant that offers up between ten and twenty ripe sweet tomatoes each day or say goodbye to several expensive and treasured roses. Like Scarlett in Gone With the Wind, I'll think about that tomorrow.

    My dad was in the Air Force. When I was a kid, we moved every few years. That meant a lot of good-byes. It also meant getting used to a whole new community and a whole new school each time we moved. I can still feel what it was like to have to walk into the new school—that sinking feeling in my belly, that heaviness in my throat. It would always take time for me to learn how everything worked, what was cool and what was not. It was always a struggle to find where I could fit in.

    Already shy, I didn't have much self-confidence in my friend-making abilities. I was the girl walking in the halls with her head down, panicking. When I spoke, you could hardly hear my soft voice. I was nervous and doubted myself a lot.

    It was very hard not having a history with everyone else. I was an outsider. But what I did have was soccer. Wherever I went, I knew that I could fit in with the soccer ball. The soccer team meant a familiar place and immediate friends for me. I could express myself and feel good about myself on the field. Playing hard helped to get rid of all my nervousness.

    Throughout our lives, our self-respect goes down when we feel like a failure, and it goes up when we feel successful. Doing something well, being praised, and feeling loved goes a long way. We all need to explore opportunities where we can be good at something and feel good about ourselves. Physical activity and sport participation is a terrific way to build up our sense of self-confidence and self-worth.

    It is not only praise or punishment that determines a child's level of confidence. There are some other important ways we shape our kids—particularly by giving instructions and commands in a negative or positive choice of words. For example, we can say to a child "Don't run into traffic!" or "Stay on the footpath close to me." In using the latter, you will be helping your kids to think and act positively, and to feel competent in a wide range of situation, because they know what to do, and aren't scaring themselves about what not to do.

    Actually, it is all in the way the human mind works. What we think, we automatically rehearse. For example, if someone offered you a million dollars not to think of a blue monkey for two minutes, you wouldn't be able to do it. When a child is told "Don't fall off the tree," he will think of two things: "don't" and "fall off the tree". That is, he will automatically create the picture of falling off the tree in his mind. A child who is vividly imagining falling off the tree is much more likely to fall off. So it is far better to use "Hold on to the tree carefully."

    Clearly, positive instructions help kids to understand the right way to do things. Kids do not always know how to be safe, or how to react to the warning of the danger in negative words. So parents should make their commands positive. "Sam, hold on firm to the side of the boat" is much more useful than "Don't you dare to fall out of the boat?" or worse still "How do you think I'll feel if you drown?" The changes are small but difference is obvious.

    Children learn how to guide and organize themselves from the way we guide them with our words, so it pays to be positive.

    The hemlock(铁杉) trees along the Wappinger Creek, New York, look healthy. However, scientist Gary Lovett says the white balls which provide protection for the bugs are created by a tiny insect. It's hard to believe the tiny bug could kill a tree. However, trees can end up with millions and millions of the pests. When there are that many, it ends up killing the tree.

    The bug from East Asia is slowly killing trees across the USA. The trouble-making bug is just one of many invasive(入侵的) pests that have slipped into the United States. They can hurt other living things in their new home.

    Many invasive pests arrive on wooden pallets(运货板) piled inside shipping containers. They support and separate goods, and keep them from sliding around. Invasive pests often tunnel into the pallets. How can we stop pests from riding on pallets? Lovett says new rules are needed. The companies that make pallets don't want more rules. Congress has added an amendment(修正案) in the 2018 Farm Bill to try and prevent this problem. However, Lovett is not hopeful it will make much of a difference. Pallets are checked by inspectors. Many are sprayed with bug-killing pesticide. "I believe in the system," said Brent McClendon, president of The National Wooden Pallet and Container Association. He also said shipping containers are checked very carefully.

    Still, each year 13 million containers are shipped to the U. S. Each is full of wooden pallets. Lovett says: "Inspectors can't possibly check everything. All it takes are a few bad pallets; we should get rid of wooden pallets." He believes pallets should be made of plastic or eco-composite wood. Eco-composite wood is a mix of wood fiber and plastic. Insects cannot hide into it. One problem is that these choices cost more. They may be worth the extra money, though. Invasive pests cost the U.S. $5 billion a year. Trees don't just die in forests. They also die in cities and our yards. Then, they need to be replaced. That costs money, too.