Try this: For an entire day, forget about the clock. Eat when you're hungry and sleep when you're tired. What do you think will happen?

    You may be surprised to find that your day is much like most other days. You'll probably get hungry when you normally eat and tired when you normally sleep. Even though you don't know what time it is, your body does.

    These patterns of daily life are called circadian rhythms, and they are more than just habits. Inside our bodies are several clocklike systems that follow a roughly 24-hour cycle. Throughout the day and night, our internal clocks direct changes in temperature, body chemicals, hunger, sleepiness and more.

    Everyone's rhythms are unique, which is why you might like to stay up late while your sister always wants to go to bed early. But overall, everyone is programmed to feel tired at night and energetic during the day.

    Scientists have known for a long time that the light of day and the dark of night play important roles in setting our internal（内部的） clocks. Now, new discoveries are giving scientists insights into how these clocks work.

    Learning about our body clocks may help scientists understand why problems arise when we act out of step with our circadian rhythms. For example, traveling across time zones can make people wake up in the middle of the night. Regularly staying up late can make kids do worse on tests and quizzes. And working shifts at night leads to higher rates of heart disease, diabetes and obesity.

    “There is a growing sense that when we eat and when we sleep are important parts of how healthy we are,” says Steven Shea, Director of the Sleep Disorders Research Program at Brigham and Women's Hospital in Boston.

    Scientists still aren't sure why the timing of sleep matters so much, Shea says. But research findings suggest that our circadian rhythms are more important than we give them credit for.

    “During the night, we are prepared to sleep,” Shea says. “During the day, we are prepared to eat and move around. If you reverse (颠倒)what you are doing, everything is out of phase. That can have unfavorable consequences.”

    In England, people often talk about the weather because they can experience (经历) four seasons in one day. In the morning the weather is warm just like in spring. An hour later black clouds come and then it rains hard. The weather gets a little cold. In the late afternoon the sky will be sunny, the sun will begin to shine, and it will be summer at this time of a day.

    In England, people can also have summer in winter, or have winter in summer. So in winter they can swim sometimes, and in summer sometimes they should take warm clothes.

    When you go to England, you will see that some English people usually take an umbrella (伞)or a raincoat with them in the sunny morning, but you should not laugh at them.

    If you don't take an umbrella or a raincoat, you will regret (后悔) later in the day.

    Fikiri Kiponda's path from accountant to marine (海洋的) conservationist was sparked by a chance encounter.    After securing his dream job, Kiponda decided he wanted more. He wasn't quite sure what he was looking for until he ran across some turtle hatchlings.

    He didn't know it was turtle. Fortunately enough he got the right person to ask and he got motivated. That person was Nkindi, a staff member at the Watamu Conservation project who later invited him to volunteer on the project. He later left his accounting job and fully devoted himself into the world of sea turtles. Now，he runs and spends his time nursing critically endangered sea turtles back to health.

    Sea turtles have been around for nearly 110 million years and are now considered highly endangered. Their preservation rests on activities of conservationists such as Kiponda as these turtles face numerous threats and signs of their extinction in the next 50 years.

    Local fishermen traditionally catch them to supplement their own low catch rates and sell them for their oil. As changes are made to accommodate more hotels for tourists, there is less available beach land for turtle nesting.

    Kiponda's passion has now spread to his community, changing their attitude towards sea life preservation with his “by-catch release programme.”

    Through this program, fishermen are now paid for returning turtles accidentally caught in their fishing nets. The healthy ones are tagged and released into the marine park while he takes care of sick and injured turtles back to health.

    Before the launch of pioneering spirit like this, turtles caught by fishermen were used for their meat and their oil extracted (提炼) for its medicinal properties.

    “Releasing the turtle back into the ocean is a very good feeling, like, you feel like you've done something concrete and I guess everybody would love to do that...so I guess it's unique work.”

    Sitting on the peaceful coast of Galapagos Islands. Ecuador, watching the sun move quietly into the sea, you shouldn't forget that Charles Darwin (1809-1882) arrived here in 1835. He stayed on the islands for five weeks, observing various animals. This finally inspired (启发) his famous work, On the Origin of Species. You can certainly follow Darwin's footsteps and enjoy a trip from four to seven days to the islands. The islands are certainly a paradise (天堂) for wildlife, as there are no natural killers on the islands and the number of boats and visitors is under government control. Though you cannot walk freely as Darwin did about 200 years ago, each day is as impressive as it could be. The most well-known animal of the Galapagos is the giant tortoise(巨型海龟), which can be seen moving slowly around the highlands of Sanra Cruz, the second largest island in the archipelago(群岛). Some of these creatures are so old that they might have been seen in their youth by Darwin himself. Despite strict control over activities and timing, your stay on the Galapagos will be remembered as a chain of incomparable pictures: diving with sea lions that swim and play within inches of you; feeling small sharks touch your feet as you swim; and, most magically, seeing a whale and her baby surface with a great breath of air. Travelling between the islands and observing the wildlife that so inspired Darwin, you will feel as though you are getting a special view of an untouched world. At night you will sleep on board the ship, leaving the wildlife in complete occupation of the islands, which are as undisturbed now as they have been since the beginning of time.

    The Renaissance marks a period of human awakening. In this article we are going to explore the inventions during this period which have helped change the life and progress of mankind.

    Clock

    The first mechanical clock was invented in the early 1300's. Galileo, an Italian scientist, discovered the pendulum (钟摆) around 1602. The pendulum greatly improved the movement of the hands of a clock. The average error with the pendulum varied only by seconds each day. Before this the error was from 10 to 15 minutes a day.

    Eyeglasses

    In the late thirteenth century, paintings first appeared with people wearing or holding eyeglasses. From these paintings, we know that eyeglasses were invented in Italy. Around 1300 the Venetian Glassmaker's Guild made it illegal for cheap glasses to be made. By 1352, eyeglasses were only worn by well-educated rich men. In 1456, the invention of the printing press allowed books to become widespread. Once people owned books, reading glasses began to be seen in the hands of common people. In 1623, the Spanish invented the first graded eyeglasses.

    Flush toilet (抽水马桶)

    Sir John Harrington, godson to Queen Elizabeth, made the first flush toilet for himself and his godmother in 1596. He was teased by his friends and never made another one.

    In 1775, Alexander Cummings reinvented the flush toilet more commonly called the water closet. Two years later in 1777, Samuel Prosser applied for and received a patent for it.

    Wallpaper

    In 1496, the first paper factory came into operation in England. English artists soon make wallpaper for decoration. For the next 200 years England was a large producer of wallpaper for Europe. Before wallpaper was invented, only wealthy people could afford to decorate the walls of their houses.

    Large gatherings such as weddings and conferences can be socially stressful. Pressure to learn people's names only adds to the stress. A new facial-recognition app could come to the rescue, but privacy experts recommend going on with caution.

    The app, called SocialRecall, connects names with faces via smartphone cameras and facial recognition, potentially avoiding the need for formal introductions. "It breaks down these social barriers we all have when meeting somebody," says Barry Sandrew, who created the app and tested it at an event attended by about 1,000 people.

    After receiving an invitation to download SocialRecall from an event organizer, the user is asked to take two selfies and sign in via social media. At the event, the app is active within a previously defined geographical area. When a user points his or her phone camera at an attendee's face, the app identifies the individual displays the person's name, and links to his or her social media profile. To protect privacy, it recognizes only those who have agreed to participate. And the app's creators say it automatically deletes users' data after an event.

    Ann Cavoukian, a privacy expert who runs the Privacy by Design Center of Excellence praises the app's creators for these protective measures. She cautions, however, that when people choose to share their personal information with the app they should know that there may be unintended consequences down the road with that information being used in another context that might come back to bite you."

    The start-up has also developed a version of the app for individuals who suffer from prosopagnosia, or "face blindness", a condition that prevents people from recognizing individuals they have met. To use this app a person first acquires an image of someone's face, from either the smartphone's camera or a photograph, and then tags it with a name. When the camera spots that same face in real life, the previously entered information is displayed. The collected data are stored only on a user's phone, according to the team behind the app.