Poor environment is connected with poor health. Now a new public-health     1     (tend)is becoming apparent: Making indoor air cleaner.

Let’s take schools for example. Across Denmark, France, and Sweden, researchers found that indoor-air quality in 66% of classrooms fell short     2     healthy standards. Outdoor-air pollution can get inside buildings — childhood     3     (expose)can affect their physical development and academic performance, and cause cancer.

The problem extends well beyond classrooms. Many people spend more than 90% of their time     4     (stay)indoors. Spaces in buildings with poor air may cause a range of diseases — headaches, shortness of breath, coughs and discomfort of eye, nose, throat and skin. Poor air     5     (blame)for decreased productivity in the past few years.

Covid-19 has brought a new urgency to the matter     6     (great). More investment would be well spent. Better indoor air improves academic development — math     7     reading scores go up. Meanwhile pupils are     8     (attentive)in class. Poor air indoors is the     9     (forget)part when people improved public health. Covid-19 should lead policymakers to focus on the problem,     10     is of great importance for people’s well-being.

2 . Island Getaways

Beautiful beaches, rich cultures and untouched pockets of wilderness are just a few attractive characteristics of the best island vacations. Each of the islands listed here has something extra that keeps travelers charmed.

Principe

West of Africa's mainland, small Principe offers blue seas, yellow beaches, jungle peaks, whale-watching with received plantations to visit and locals to meet. Pleasant eco-resorts help, too. Principe is amazingly safe and welcoming to visitors, particularly ecotourists, for whom the advancing jungle is a delight.

Bryher

The handsomest of the Isles of Scilly, 25 miles from Land's End, Bryher accompanies rose gardens with a windy wild coastal path. You can follow the coastal path visiting the charming beaches including Rushy Bay which is a must with fine white sand and clear waler. You can also take a hike up one of the hills to enjoy amazing views across Scilly and out to a Bishop Rock Lighthouse witnessing the past glory.

Astypalea

Butterfly-shaped Astypalea, an unspoilt Greek island, which banned cigarettes in 2019. Pretty yellow beaches as well as churches in the math town. Chora Chora, the island's capital, built on a hill with a breathtaking view of the Aegean Sen. On the top of the hill overlooking the village, sits Querini castle which used to protect the island during the Middle Ages, but now it is the main attraction of Astypalea.

Dominica

Commonly known as The Nature Island, Dominica sticks out up from the shiny waters of the Caribbean to serve as a fairy land for travelers seeking thrills in a place that lime has forgotten. The best-kept secrets of the Caribbean arc lush rainforests, towering mountains, rushing rivers and welcoming waterfalls with volcanic wonders adding unique beauty to Dominica.

As is well-known to us all, ants move between their home and sources of food frequently,     1     which their survival depends. Motsch and his colleagues wondered if ants on the move could get     2     （stick）in the jams.

Therefore, they controlled traffic density（密度）by constructing bridges of a     3     （vary）of widths between ants' home and a source of food.     4     only goal was to try to find out at what point they would have a traffic jam. They just waited and watched. But the ants never, at one point, just stopped.

The flow of ants did increase as ants started to fill the bridge. But it never slowed down, even when the bridge was crowded with ants. The researchers then     5     （far）looked at how the behavior of an individual ant affected traffic. They found when ants     6     （sense）overcrowding, they adjusted their speeds and avoided entering high-density areas and running into each other, thus     7     （prevent）jams.

Can ants help us solve our own traffic problems? “Not likely,” says Motsch. That's     8     when it comes to getting from point A to point B as fast as possible, human drivers put their own goals first. Ants have no choice but     9     （be）more cooperative in order to feed     10     （they）.

7 . Our carbon footprint is the estimated amount of carbon dioxide given off as we go about our daily lives. While the global average carbon footprint is about 4 tons per person each year, Americans contribute approximately 20 tons of greenhouse gas per person each year. Compared to other countries, even those who use the least amount of energy in the US still contribute double the carbon emissions than the global average per person. And, not surprisingly, a person's carbon footprint increases in size as his or her income increases.

How is it possible that people in the US who live simple lifestyles, e.g., children or the homeless, make such large contributions to greenhouse gas emissions? The answer is simple: Each US citizen has access to various basic government services such as firefighting and police departments, road and bridge repair, libraries, prisons, the military, etc. When these public services are divided equally among the entire US population, it significantly raises the carbon footprint per person.

While it is admirable to make changes in lifestyle to reduce a carbon footprint, in reality, it is very difficult to do. The MIT study revealed that a "rebound effect" occurred when someone made an effort to reduce his carbon footprint. Take the example of a person who made the deliberate choice to buy a hybrid(混合动力的)car instead of a large SUV to save money on gas costs. Very often that person would use the money he saved to do something else, e.g., take a long airplane trip. In this case, just one long airplane trip produces more CO₂ emissions than driving the large SUV for a year. This ends up having a negative impact on a person's carbon footprint by making it bigger!

Can Americans reduce their carbon footprints? According to the study, it is possible, but it would require lifestyle changes such as giving up long distance travel and buying fewer smartphones and tablets that have large energy cost to produce and deliver. Another way is to add a CO₂ tax on food, housing, and transportation. Unless we can find a way to reduce our carbon footprints, the price we may ultimately have to pay is much higher than the amount Americans will ever have to pay in taxes.

Xi'an,or Chang'an as it was called for many centuries,has been a built-up urban area for over 3,000 years,and once     1    （serve）as capital for 13 dynasties.It is home     2     many immovable cultural heritages,three of     3     are on the UNESCO 's world cultural heritage list.

These days,the city has made     4    （effect）exploration in building modernity while preserving historical legacy（遗产）.A recent piece of news     5    （announce）by Shaanxi's cultural relic authority caused nationwide attention,that a ruin of ancient capital dating back to Qin Dynasty was unearthed during the construction of the Xi 'an MetroLine5.In order to protect the ruin,the metro line may have to change     6    （it）route.

    7     （face）the heavy and important task of protecting cultural relics while promoting urban construction,Xi’an made active    8    （attempt）.Rails of the metro system are built 15 to 20 meters underground in order to protect the ancient tombs which are     9     （usual）buried in the layer within5meters from the surface level.Besides,the metro constructors have also painted the walls inside the stations with historical stories,presenting       10     visual feast for citizens.

9 . Japanese botanist Akira Miyawaki, beginning in the 1970s, pioneered a method of planting young native species close together to quickly create tiny forests on urban wasteland. He found that protected areas around temples in Japan contained a huge variety of native plants that co-existed to produce adaptable and diverse ecosystems. The forests were layered together from four categories of native plantings: main tree species, sub-species, bushes, and ground-covering herbs. Using this four-category system, along with his explorations of the vegetation in Japan, Miyawaki designed his own system for planting forests.

Miyawaki forests can grow into mature ecosystems in just 20 years-about 10 times the growth speed of a traditional forest, explained Kazue Fujiwara who worked with Miyawaki. According to Fujiwara, the planting should center on the primary trees of the location. Native species require no maintenance (养护) after the first two years and are more likely to survive and grow well in the local environmental conditions. What's more, they provide an ideal home for endangered species.

When Shubhendu Sharma learned about Miyawaki's forest creation technique in 2009, the botanist created a forest at the Toyota factory in India where Sharma worked as an engineer. Shortly, he started a company to create similar forests, researching the method and trying it in his own backyard. He described his work in a 2014 TED Talk, and released his version of the instructions so anyone could learn how to create their own small native forest. Since then, Sharma's company, Afforestt, has helped plant forests in 44 cities.

Now, Miyawaki-style urban forests have been springing up across Europe. Cities in Asia are embracing the idea, with Pakistani minister announcing plans for 50 Miyawaki forests in Lahore, and Indian officials setting a target to plant 1,000 in Chennai.