Some people may think I'm crazy when I say “work is rest”. But that's the way it is — we need to rest. Without rest, we will die. At a minimum, we won't have the energy to work.

    Nobody forces us to be so stupid about this. We just don't know how to rest properly. We rest in ways that are not restful, even stressful. Some of our ways of rest interfere with our working energy. Instead of sleep, we go to the movies and clubs, drink or have a smoke with friends. This is because we misunderstand the meaning of “rest”.

    We should remember that rest means not working, both physically and mentally. Only then is it real rest. When tired, rest. It's simple. Actually, dogs and cats are smarter about this than people. People are stupid enough to rest in ways that destroy their capacity to work.

    Rest and work always go together. There must be a balance: work during the day and rest at night. When the sun comes up, one has plenty of strength to work well and enjoy it. In other words, rest is a kind of investment, so that one has the strength and energy to continue working. So we need rest to work, recognizing that we can't have one without the other. Rest is what recharges our batteries. We need enough time to charge up adequately to the tasks we undertake. Thus, we need to rest correctly; otherwise, illness will occur and also can affect the efficiency of our work.

    Rest can't be skimped. Without enough rest, good work is impossible. This is why we say that rest is another kind of work.

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    For World Heritage(遗产) Sites, you probably think of places connected with ancient art and culture, and historical buildings. But there are a few of the more unusual sites.

    Citadel of Haiti.

    These monuments were built at the end of the nineteenth century when Haiti became independent and the many thousands of black slaves in Haiti were free for the first time. These ex-slaves built the monuments, which The World Heritage List (WHL) describes as a true symbol of liberty.

    The Darjeeling Himalayan Railway in India.

    This railway was opened in 1881 and is still operating today. It crosses a difficult area of mountain landscape and it is a great example of railway engineering. The WHL says that it is the first and still the most outstanding example of a hill passenger railway.

    Borders of France and Spain.

    This is an area of great natural beauty and the mountains have many interesting geological shapes. Besides, people there still use a type of agriculture that used to be common in mountainous areas of Europe but has almost completely disappeared in modern times. The WHL says it shows us about past European society through its landscape of villages, fields and mountain roads.

    Alto Douro, Portugal.

    This is an area in the North of Portugal where wine has been produced for thousands of years. Nowadays it is world-famous for the port wine that is produced there. The WHL says that this long tradition of wine making has produced a cultural landscape of outstanding beauty that reflects its technological, social and economic development little by little.

    Many leading AI researchers think that in a matter of decades, artificial intelligence will be able to do not merely some of our jobs, but all of our jobs, forever transforming life on Earth.

    The reason why many reject this as science fiction is that we've traditionally thought of intelligence as something mysterious that can only exist in biological organisms, especially humans. But such an idea is unscientific.

    From my point of view as a physicist and AI researcher, intelligence is simply a certain kind of information-processing performed by elementary particles(基本粒子) moving around, and there is no law of physics that says one can't build machines more intelligent than us in all ways. This suggests that we've only seen the tip of the intelligence iceberg and that there is an amazing potential to unlock the full intelligence that is potential in nature and use it to help humanity.

    If we get it right, the upside is huge. Since everything we love about civilization is the product of intelligence, amplifying(扩大) our own intelligence with AI has the potential to solve tomorrow's toughest problems. For example, why risk our loved ones dying in traffic accidents that self-driving cars could prevent or dying of cancers that AI might help us find cures for? Why not increase productivity through automation and use AI to accelerate our research and development of affordable sustainable(可持续的) energy?

    I'm optimistic that we can develop rapidly with advanced AI as long as we win the race between the growing power of our technology and the knowledge with which we manage it. But this requires giving up our outdated concept of learning from mistakes. That helped us win the race with less powerful technology: We messed up with fire and then invented fire extinguishers, and we messed up with cars and then invented seat belts. However, it's an awful idea for more powerful technologies, such as nuclear weapons or superintelligent AI—where even a single mistake is unacceptable and we need to get things right the first time.

    The popular wisdom for years has been that drinking in moderation (适度)—that's one “standard” drink a day for women and two for men-is linked to a lower risk of cardiovascular (心血管的) disease. But recent studies are casting some doubt on that long-held learning. Science now says it depends on your age and drinking habits.

    A 2017 study of nearly 2 million British with no cardiovascular risk found that there was still a modest benefit in moderate drinking, especially for women over 55 who drank five drinks a week. Why that age? Alcohol can influence the substance in the blood in positive ways, experts say, and that's about the age when heart problems begin to occur.

    Also, a 2018 study found that drinking more than 100 grams of alcohol per week—equal to roughly seven standard drinks in the United States or five to six glasses of wine in the UK—increases your risk of death from all causes and in turn lowers your life expectancy. Links were found with different forms of cardiovascular disease, with people who drank more than 100 grams per week having a higher risk of stroke, heart failure.

    Another 2018 study found that consistently drinking a moderate amount of alcohol, within recommended guidelines, had a protective effect on the heart over time. Unstable drinking habits were associated with a higher risk of heart disease, which the authors reflected might indicate broader lifestyle changes, such as poor health or stress. Former drinkers were also at greater risk.

    Overall, however, the latest thinking is that any heart benefit may be outweighed by other health risks, such as high blood pressure, certain cancers and liver damage.

Women who drink are at a higher risk for breast cancer; alcohol contributes about 6% of the overall risk, possibly because it raises certain dangerous hormones in the blood. Drinking can also increase the chance you might develop liver, mouth and oral cancers. One potential reason: Alcohol weakens our immune systems, making us more likely to inflame (发炎)—a driving force behind cancer.

    A trip to Paris is not complete without a visit to the Eiffel Tower. To get the most out of your visit read our tips below:

    Visit at Night

    Riding up the Eiffel Tower at night and looking out over the streets of Paris, you'll see why Paris is known as the “City of Light”. At street level, the spotlights on the top of the Tower and the reflections (倒影) of the Tower in the Seine (塞纳河) are sights not to be missed.

    Purchase (购买) Your Ticket in Advance Online

    Avoid the long ticket lines at the Eiffel Tower by purchasing your ticket online from the Eiffel Tower website.

    You'll pick a time to visit and then select whether to print out the ticket or display it on your phone or iPad, a convenient choice if you buy your ticket in Paris without a printer.

    Don't Bring Valuable Objects with You

    Before entering the Eiffel Tower, your bags will be examined by a security officer. If an item you are carrying sets off the metal detector, the officer will take you away from the line for further inspection. Probably you will miss the chance to go up the Eiffel Tower.

    Have Drinks and Snacks at the Eiffel Tower

    If you're like us, after an exciting trip to the Eiffel Tower, you'll be ready to rest your legs and have a relaxing snack and a drink in a Parisian cafe. Across the Seine in the Trocadero area, there are many elegant cafes. The atmosphere is great, but the prices are in the stratosphere (极高水平). Actually, the perfect place for common visitors to eat and drink is on the Eiffel Tower itself.

    A large body of research has been developed in recent years to explain many aspects of willpower. Most of the researchers exploring self-control do so with an obvious goal in mind: How can willpower be strengthened? If willpower is truly a limited resource, as the research suggests, what can be done to make it stay strong?

    Avoiding temptation (诱惑) is an effective method for maintaining self-control, which is called the "out of sight, out of mind" principle. One recent study, for instance, found office workers less attracted to candy in the desk drawer than that on top of their desks, in plain sight.

    The research suggesting that we possess a limited reservoir of self-control raises a troubling question. When we face too many temptations, are we to fail? Not necessarily. Researchers don't believe that one's willpower is ever completely exhausted. Rather, people appear to hold some willpower in reserve, saved for future demands. The right motivation allows us to tap into those reserves, allowing us to carry on even when our self-control strength has been run down. High motivation might help overcome weakened willpower-at least to a point.

    Willpower may also be made less vulnerable (脆弱) to being exhausted in the first place. Researchers who study self-control often describe it as being like a muscle that gets tired with heavy use. But there is another aspect to the muscle comparison, they say. While muscles become exhausted by exercise in the short term, they are strengthened by regular exercise in the long term. Similarly, regular practices of self-control may improve willpower strength.

    The evidence from willpower-exhaustion studies also suggests that making a list of resolutions on New Year's Eve is the worst possible approach. Being exhausted in one area can reduce willpower in other areas, so it makes more sense to focus on a single goal at a time. In other words, don't try to quit smoking, adopt a healthy diet and start a new exercise plan at the same time. Taking goals one by one is a better approach. Once a good habit is in place, Baumeister says, you'll no longer need to draw on your willpower to maintain the behavior. Eventually healthy habits will become routine, and won't require making decisions at all.