【推荐3】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.     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.     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.

    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.     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.     5    

【推荐3】The skies over Latin America’s largest city are set to witness a futuristic aerospace revolution after the Brazilian airline Gol reached an agreement that could see it transport regular passengers around São Paulo in hundreds of low-cost zero-emission electric air taxis.

Dómhnal Slattery, chief executive of the Dublin-based firm Avolon, which will provide the aircraft to Gol and recently placed an order for 500 of the aircraft from their British manufacturer, admitted helicopters were the “kingdom of the wealthiest”.

But the Avolon boss claimed the introduction of VA-X4 eVTOLs (electric vertical(垂直的) takeoff and landing) aircraft to São Paulo would be a gamechanger for regular passengers once the taxis, which look like a futuristic cross between a helicopter and a glider, were delivered in late 2024 or 2025.

“Our basic estimate (估计) at the moment is that the operating cost here for this aircraft will be equal to $1 per passenger over a 25-mile trip,” Slattery told the Financial Times. “Which is almost equal to an Uber ride.”

Few cities are crying out for such a revolution more than São Paulo, a sprawling metropolis with more than 12 million citizens and choked by a fleet of 8.6m vehicles.

In the late 1990s, the congestion (拥塞) became so bad in what is now the world’s fifth biggest city after Tokyo, Delhi, Seoul and Shanghai that authorities were forced to introduce a number plate rotation (循环) system for vehicles.

Stephen Fitzpatrick, the head of the British aerospace manufacturer that produces the aircraft, Vertical Aerospace, said the flying taxis would be ideal for Brazil’s biggest city and will “transform how we travel around high population density cities that are crowded with traffic”.

The Bristol-based Vertical Aerospace was founded in 2016 and promises to pioneer “a new era in vertical transport”.

“We’ll be looking to Asia after São Paulo,” Avolon’s chief commercial officer, Paul Geaney, told Reuters.

【推荐1】Growing at high speed and absorbing huge amounts of atmospheric carbon dioxide, could seaweeds be the key to fighting climate change? Scientists in Australia think so. In Australia, scientists are taking advantage of the power of seaweeds to absorb CO₂ at a rate that equals to the Amazon rainforest!

Kelp (巨藻) is one of the most common seaweeds. It has many types and grows at great speed. Giant kelp, for example, can grow up to 50 cm per day. Seaweeds use photosynthesis (光合作用) to absorb CO₂, and grow biomass. Seaweeds are thought to absorb nearly 200 million tonnes of our globe’s CO₂ per year.

Pia Winberg, founder of Australia’s first land-based commercial seaweed farm, suggests that growing more seaweeds could be an essential tool in the fight against climate change. “If we used the infrastructure we have in the ocean and created seaweed islands, we would actually remove many climate change issues we have today,” she said.

The Great Southern Reef is an 8,000-km network of reefs in Australia. Golden kelp forms the backbone of the network. With many other species, including giant kelp and bull kelp, growing there, it is a good place for series of relevant projects. The Great Southern Reef project managed by an independent team of seience professionals is working to promote the recognition and management of Australia’s kelp forests. The project estimates that if these kelp forests were cultivated in just 0.001% of the ocean’s surface, the amounts of the CO₂: they absorb could offset (抵消) the carbon emissions of the global aquaculture (水产养殖) industry.

Of seaweeds’ potential, there’s a long chain of wins with this.

【推荐2】Sea ice in the Antarctic (南极) area fell to a record low this year. The drop is a result of rising temperatures worldwide. And there is no quick method to make up for the ice drop, and the recovery (恢复) has a long way to go, scientists said recently in a new study.

Antarctica’s smallest summer ice cover fell further to a new low in February. This year’s sea ice minimum (最小值) is 20 percent lower than the average (平均值) over the last 40 years. The sea ice loss equals an area nearly 10 times that of New Zealand.

The warming of Earth’s surface driven by the burning of coal, gas and oil has made Antarctica more likely to suffer from extreme (极端的) events. And the result is almost “certain” to get worse, the study said. Climate change will “lead to increases in the size and rate”of heat waves, broken ice shelves and drops in sea ice, it said.

The effects of the Earth’s warming on Antarctica and the surrounding ocean have been uncertain. Scientists have had problems measuring how much the Earth’s warming is altering the thickness of Antarctic ice.

But from events such as the fast drop in sea ice, it is “scientifically reasonable” to suppose that extreme events are going to become worse as temperatures rise worldwide, said Martin Siegert of the University of Exeter, another study co-writer.

Siegert described the temperature increase as completely surprising. Siegert added that luckily the event had happened during the Antarctic winter, instead of summer, or it would have caused melting (融化) on the surface of the East Antarctic ice cover, which has so far been saved from melting.

Siegert used the term “fragile”, meaning easily broken or damaged, to describe Antarctica. “Antarctica is fragile as an environment, but extreme events test that fragility,” he said.

【推荐3】Mont Kilimaniaro is among Africa’s most breathtaking sites, but hard times have come to the plains below. Death is all around and it’s tragic to behold. The cause is a lack of rainfall in a land where on the contrary there is still plenty of water. Underground springs fed by snowmelt from the mountain, still create swamps(沼泽). The problem is that the absence of rain means grasses and other essential plants are not growing, and the animals that depend on them are dying from a lack of nutrition.

The elephant herds here are among the most successful in the continent. They’re closely monitored and conservationists have given them names. But even these great beasts are dying too, what is for the smaller ones?

A drought induced hunger. Since the start of June almost 60 elephant deaths have been recorded. More than half calves were killed by starvation due to their mothers’ failure to produce milk. Tolstoy, a male, was named after Russian. He was 5-year-old at the time of his death. And he was one of the greatest tuskers like one of the greatest alive.

Very sad story. There are some of the last relatively undisturbed elephants in Africa. While poaching(偷猎)has been destructive elsewhere，these animals have been largely spared. Right now, however, the problem they face here is a drier climate which poses the greatest threat to their survival.

There are plenty of people here who care deeply about these elephants, but the sad truth is that conservationists are powerless to stop the dying. Only fresh rainfall and new plant growth can do that. We are waiting for the rains. If the rains don’t come before the end of the year, the death rate will only increase.