How the Grand Canyon (大峡谷) was created remains one of the geology's greatest mysteries. Some evidence suggests that the process was a gradual one in which the Colorado River (which runs through the canyon) slowly cut deeper and deeper into the ground over millions of years. But volcanic rock samples taken from the canyon now suggest that the canyon was down-cut instead.

    Down-cutting is when a flood of water rushes over a landscape (地形) with enough force to cut deeply into the ground and leaves behind a canyon. Such a flood is usually released when a natural or man-made dam (堤坝) bursts.

    Robert Webb, a research geologist, says natural dams seem to have formed and broken across the Colorado River several times during the last million years. The dams were built when lava(熔岩) from the eruptions of nearby volcanoes flowed into the river. The lava hardened into hard rocks and blocked the river, causing it to back up and form a lake. Each time the lake grew so huge that it broke the rock dam, releasing a flash flood that furthered the down-cutting process and deepened the canyon.

    Down-cutting is not just an earthly event. Satellite photos sent back from Mars suggest that the process has happened there, too, say many other researchers.

    The photos, taken by the Mars Global Surveyor, indicate that an enormous lake existed on Mars 3.5 billion years ago. The lake spilled into a large nearby hole. One edge of the hole broke, releasing a flash flood that quickly carved out a grand canyon.

    The existence of down-cutting on Mars is just one more piece of evidence that the cold, dry planet was once warm and wet.

    Lawns（草坪）are some of the most common things in the world until you really start thinking about them. That's when you realize that they make no sense. Why do people keep these uninteresting, pointless little plants outside their homes? They're not beautiful like flowers, they don't provide food and you have to take care of them constantly.

    Israeli bestselling author Yuval Noah Harari thought these deeds were weird too. He looked into their history and ended up with an interesting story.

    No one considered putting patches of grass outside their homes in ancient times. That changed in the Middle Ages, when French and English kings and nobles started putting patches of grass at their castle entrances.

    “Well-kept lawns demand land and a lot of work,” wrote Harari in his book. “In exchange, they produce nothing of value.” Peasants could never afford to waste their time or land on lawns, so these lawns were a perfect status symbol（身份的象征）for nobility（高贵）.

    When the Industrial Revolution began in the 18th and 19th centuries, the middle classes started being able to afford their own suburban（郊区的）houses. And guess what became the suburban status symbol? A perfectly kept lawn.

    The popularity of lawns continued to grow, taking over public event spaces and sports. In the past, people played sports on all kinds of surfaces—dirt, ice, sand. But in the last couple centuries, they made the switch to green grass.

    “Grass is nowadays the most widespread crop in the USA after corn and wheat,” Harari continued. Lawns spread beyond Europe and the U.S, and they're now status symbols around the world.

    Suburban people may not realize it, but they care for lawns just because centuries ago, French and English kings wanted to show off by intentionally planting something useless. It's strange that people should continue to spend so much time and money on what's really a leftover（遗留物）from the Middle Ages. When you plan your house, you can shake off（摆脱）the cultural leftover and imagine for yourself a rock garden or some other new creation.

    Keeping a busy social life among lots of friends may keep people thinner than spending hours doing some exercises, according to scientists. They say that socializing and meeting with friends help increase levels of brown fat in the body which burns calories to produce heat.

    Living in an exciting social environment was found to reduce fat in mice's belly by half over four weeks, even if they ate more.US researchers say that social excitement aids weight loss by turning white fat into brown fat. White fat stores calories and makes us fatter, while brown fat burns energy to produce heat. Turning white fat into brown fat is extremely difficult, normally requiring long-term stay in cold conditions or exciting part of the body's nervous system.

    However, scientists from Ohio State University now think that having a busy social life is an even more effective way of changing white fat into brown fat. The team came up with their theory by studying the effects of various living environments on mice. Those, who lived alongside a greater number of mice, had more space and toys to excite themselves and they lost far more weight over the course of the study than their “couch potato” fellows.

    Study's author, Dr Mattew During whose team's findings appear in the journal Cell Metabolism, said,“I'm still amazed at the degree of fat loss that occurs.” Explaining how new technology had threatened face-to-face socializing, he added,“It's not just a sedentary (久坐的)lifestyle and high calorie foods, but an increasing lack of social activities.” Co-author Dr Lei Cao said,“Loneliness is a potential factor for cancer and death; it's equal to cigarette smoking to a certain extent. Social activities are very vital.”

    In its best times on the nineteenth century, thatch (茅草屋顶) played an important role in protecting British homes from the weather. But new technologies since have led to a rapid decline in thatching and many of the thatched cottages that remain have been changed beyond all recognition by developers or have run into disrepair, a rather upsetting reminder of a bygone age.

    A Welsh company, however, is trying to breathe new life into some of the last traditional thatched cottages in western Wales by repairing them and letting them out as holiday homes. Called "Under the Thatch", the company is run by Greg Stevenson, who lives in his own thatched cottage in Ceredigion. An architectural historians by training, he repairs old buildings in old-fashioned ways.

All the cottages are in attractive locations around southwest Wales. Unlike most holiday homes, the cottages are let all year round—chiefly because Greg prices them lower than many holiday properties( 房屋) and he'd prefer that properties are rented just above cost price than not used at all. And with that comes a bargain or two: it's common for a property to go for as little as£35 a night. Consequently occupancy for properties with " Under the Thatch" is at 95 percent( the average in Wales is 35 percent).

    Its success has meant that Greg has been able to buy up more old cottages and bring them back into the community. Greg has also diversified from offering only thatched cottages: he now lets out a variety of rare accommodations dotted around western styles , including a renovated(修复的) train carriage and two gypsy caravans which were used by Romanies.

    Most of his thirty properties are run using environmentally friendly technologies. Including solar panels and recycled furnishings. But most importantly, what the cottages all have in common is that they bring back life to local communities. Spend a weekend "Under the Thatch" rather than in a holiday home, buy local food and visit nearby restaurants, and you will be contributing to the local economy.

Any schoolchild knows that a whale breathes through its blowhole. Fewer know that a blowhole is a nostril （鼻孔） slightly changed by evolution into a form more useful for a mammal that spends its life at sea. And only a dedicated expert would know that while toothed whales, such as sperm whales, have one hole, baleen （鲸须） whales, such as humpback and Rice whales, have two. 

Even among the baleen whales, the placing of those nostrils differs. In some species they are close together. In others, they are much further apart. In a paper published in Biology Letters Conor Ryan, a marine biologist at the Scottish Association for Marine Science, suggests why that might be. Having two nostrils, he argues, helps whales smell in stereo （立体空间）. 

Many types of baleen whales eat tiny animals known as zooplankton （浮游动物）， which they catch by filtering （过滤） them from seawater using the sheets of fibrous baleen that have replaced teeth in their mouths. But to eat something you first have to find it. Toothed whales do not hunt by scent. In fact, the olfactory bulb-the part of the brain that processes smell-is absent in such creatures. But baleen whales still have olfactory bulbs, which suggests smell remains important. And scent can indeed give zooplankton away. Zooplankton like to eat other tiny creatures called phytoplankton （浮游植物）. When these are under attack, they release a special gas called dimethyl sulphide, which in turn attracts baleen whales. 

Most animals have stereoscopic senses. Having two eyes, for instance, allows an animal to compare the images from each in order to perceive depth. Having two ears lets them locate the direction from which a sound is coming. Dr Ryan theorized that paired blowholes might bring baleen whales the same sorts of benefits. 

The farther apart the sensory organs are, the more information can be extracted by the animal that bears them. The researchers used drones to photograph the nostrils of 143 whales belonging to 14 different species. Sure enough, baleen whales that often eat zooplankton, such as the North Atlantic right whale, have nostrils that are farther apart than do those, such as humpback whales, that eat zooplankton occasionally. Besides allowing them to breathe, it seems that some whales use their blowholes to determine in which direction dinner lies. 

Self- Love And Relationships

Self- love and healthy relationships cannot be separated. Self- love is the very core of any healthy relationship. Now you might wonder how my love for myself is going to make me able to have a healthy relationship. Isn't a healthy relationship all about giving? Honestly, No.

Boundaries

First and foremost, {#blank#}1{#/blank#} You will know where to draw boundaries because you value your own opinions. You will have a clear understanding of what you need, what are your values, and your limits.

Conflict Resolution

Self- love plays a very important role in conflict resolution in a relationship. {#blank#}2{#/blank#} They have more confidence and self- esteem to be able to voice their opinions.

Healthy Partner Choice

Self- love also contributes to choosing an emotionally healthy partner. {#blank#}3{#/blank#} You do not settle for less because you know what you deserve because you know your worth.

{#blank#}4{#/blank#}.

You can be only emotionally available when you do not have inner conflicts. When you are constantly fighting your own feelings, it leads to confusion and disappointment, and a lack of availability emotionally for your partner.

When you have the capacity to take care of your own emotions, you become emotionally stable. This stability allows you to better empathize with and understand your partner's experiences and emotions. {#blank#}5{#/blank#}.

Review

So now you know that self- love and health y relationships are practically inseparable. One cannot thrive without the other because they depend on each other for fulfillment and growth. They are interconnected with your happiness because self- love will motivate you to have better boundaries, a healthier understanding of your own self, and better emotional intelligence.

A．With self- love, you can solve conflicts better.

B．Loving yourself helps you set boundaries.

C．Self- love makes you choose the right partner.

D．Without self- love, you lack emotional availability.

E．Due to this, you can offer them genuine care and support.

F．When self- loving, you understand your worth.

G．Emotional Availability