Thanks to the hard work of companies like SpaceX, Virgin Galactic, and Blue Origin, space tourism is well on its way to becoming a reality. Now, California-based Orbital Assembly Corporation (OAC) expects a chance for visitors to extend their “out-of-the-world” experience by checking into a grand hotel in low Earth orbit.

The 650-foot-wide Ferris-wheel-like Voyager Space Station (VSS) will consist of two rings. The inner circle will be fitted with spacecraft stations for guests. The outer ring will house the rooms. Restaurants, bars, gyms, and scientific research labs. The solar-powered hotel will spin at speeds high enough to create artificial gravity. ensuring (确保) occupants a comfortable stay, OAC hopes to attract not just tourists but also scientists and astronauts on long-distance missions.

While the idea is attractive, making VSS a reality will take time. The team is currently building modules (舱室) for a smaller model ring. The modules will be set up in zero-gravity using semi-automatic robotic tools made for the purpose. Once they are completed, OAC engineers will attempt to create artificial gravity similar to what Mars has.

Even if the model is wildly successful, transporting the VSS modules to space will cost tens of billions of dollars. However, OAC, which expects to charge $5 million per person for each 3-day stay, is confident they will take back the expense. Though the cost may seem too much, it is cheap compared to the $55 million it costs to stay on the International Space Station (ISS).

Visitors will also be able to participate in amusing activities that are not possible on Earth. Among the planned ideas are zero gravity basketball games. Blincow says, “When you jump in the air, you jump five times higher.” Also under consideration are spacewalks to allow visitors to enjoy clear views of Earth and space. If everything goes according to plan, the company plans to start construction in 2026 and welcome the first visitors to the VSS in 2027.

Having a regular dentist check up is as essential for ensuring healthy teeth and gums (牙龈) as regular brushing and flossing. Here’s why you should make the trip.

Prevention is better than cure. Regular dental check-ups are recommended to maintain healthy teeth and gums. 【小题1】 Your dentist will advise you on what’s right for you. The aim of a check-up is to nip any problems in the bud, before you experience pain, lose teeth or have other health problems.

You’ve had a new medical diagnosis. 【小题2】 For example, high blood sugar levels in saliva caused by diabetes favour bacteria which can cause cavities (蛀牙). Some medications can cause oral problems ranging from dry mouth to stained teeth.

【小题3】 More and more adults are having orthodontic (正畸) treatment to straighten their teeth. Not only does it make a huge difference to your smile, it can also prevent gum disease, which is more likely to take hold if you struggle to clean crooked teeth.

You’ve got bad breath. Halitosis (口臭) is embarrassing and can sometimes leave a nasty taste in your mouth. You might have a hole in your tooth, an infection or gum disease. 【小题4】 Your family and friends will thank you for it.

Check for cancer. Dentists don’t just look for cavities and unhealthy gums. They can also spot mouth cancer and refer patients to hospital to see a specialist. Cases have risen by 34 per cent in the past decade, according to the Oral Health Foundation. 【小题5】

Among the annoying challenges facing the middle class is one that will probably go unmentioned in the next presidential campaign: What happens when the robots come for their jobs?

Don't dismiss that possibility entirely. About half of U.S. jobs are at high risk of being automated, according to a University of Oxford study, with the middle class disproportionately squeezed. Lower-income jobs like gardening or day care don't appeal to robots. But many middle-class occupations-trucking, financial advice, software engineering — have aroused their interest, or soon will. The rich own the robots, so they will be fine.

This isn't to be alarmist. Optimists point out that technological upheaval has benefited workers in the past. The Industrial Revolution didn't go so well for Luddites whose jobs were displaced by mechanized looms, but it eventually raised living standards and created more jobs than it destroyed. Likewise, automation should eventually boost productivity, stimulate demand by driving down prices, and free workers from hard, boring work. But in the medium term, middle-class workers may need a lot of help adjusting.

The first step, as Erik Brynjolfsson and Andrew McAfee argue in The Second Machine Age, should be rethinking education and job training. Curriculums — from grammar school to college —   should evolve to focus less on memorizing facts and more on creativity and complex communication. Vocational schools should do a better job of fostering problem-solving skills and helping students work alongside robots. Online education can supplement the traditional kind. It could make extra training and instruction affordable. Professionals trying to acquire new skills will be able to do so without going into debt.

The challenge of coping with automation underlines the need for the U.S. to revive its fading business dynamism: Starting new companies must be made easier. In previous eras of drastic technological change, entrepreneurs smoothed the transition by dreaming up ways to combine labor and machines. The best uses of 3D printers and virtual reality haven't been invented yet. The U.S. needs the new companies that will invent them.

Finally, because automation threatens to widen the gap between capital income and labor income, taxes and the safety net will have to be rethought. Taxes on low-wage labor need to be cut, and wage subsidies such as the earned income tax credit should be expanded: This would boost incomes, encourage work, reward companies for job creation, and reduce inequality.

Technology will improve society in ways big and small over the next few years, yet this will be little comfort to those who find their lives and careers upended by automation. Destroying the machines that are coming for our jobs would be nuts. But policies to help workers adapt will be indispensable.