1 . America’s youth is turning its back on tobacco. According to a study recently published by the Centers for Disease Control and Prevention (CDC), cigarette smoking among US high school students is at an all-time low. One in 5 US high school students in 2016 reported using a tobacco product within the past 30 days, an improvement from 1 in 4 students just one year before.

“These findings show the importance of continuing to implement the evidence-based strategies that we now work to reduce all forms of tobacco product use, including e-cigarettes, among our nation’s youth,” says Brian King, of the CDC’s Office on Smoking and Health and senior author of the study.

And it’s not just tobacco: Drug use among US teens is down across the board. The National Institute on Drug Abuse has published annual reports on US teens’ drug use since 1996, and the 2016 survey shows the lowest rates of illegal drug and alcohol use. Marijuana (大麻) use remained “mostly steady”. “It is encouraging to see more young people making healthy choices not to use illegal substances,” says former National Drug Control Policy Director Michael Botticelli.

All individual forms of tobacco such as cigarettes, e-cigarettes, cigars, and smoke-less tobacco saw declines in usage in 2016. Experts are especially encouraged by the decline in cigarettes, the most popular tobacco product among teens. In 2016, 11.3 percent of high school students reported using e-cigarettes, down from 16 percent in 2015.

Dr. King says adaptation is key to the decline of e-cigarettes. “We have over a half-century of science telling students about the harmful effects of tobacco use and what works best to prevent it,” says King. “E-cigarettes are the most commonly used tobacco product among our nation’s youth, and it’s critical that our proven strategies are modernized to keep pace with the changing tobacco product landscape.”

4 . A new study by scientists at Utrecht University concludes that about half of global wastewater is treated, rather than the previous estimate of 20%. Despite this promising finding, the authors warn that treatment rates in developing countries are still very low.

Humans and factories produce vast quantities of wastewater per day. If not properly collected and treated, wastewater may severely threaten human health and pollute the environment.

The authors use national statistics to estimate volumes of wastewater production, collection, treatment and reuse. “Globally, about 359 billion cubic metres of wastewater is produced each year, equivalent to 144 million Olympic-sized swimming pools,” says Edward Jones, PhD researcher at Utrecht University. “About 48 percent of that water is currently released untreated. This is much lower than the frequently announced figure of 80%.”

While the results show a more optimistic outlook, the authors stress that many challenges still exist. “We see that particularly in the developing world, where most of the future population growth will likely occur, treatment rates are falling behind,” Jones explains. “In these countries, wastewater production is likely to rise at a faster pace than the current development of collection and treatment basic facilities. This poses serious threats to both human health and the environment.”

The main problem, especially in the developing world, is the lack of financial resources to build basic facilities to collect and treat wastewater. This is particularly the case for advanced treatment technologies, which can be extremely expensive. However, the authors highlight potential opportunities for creative reuse of wastewater streams that could help to finance improved wastewater treatment practices.

“The most obvious reuse of treated wastewater is to increase freshwater water supplies,” Jones states. Treated wastewater reuse is already an important source of irrigation water in many dry countries. However, only 11% of the wastewater produced globally is currently being reused, which shows large opportunities for expansion.

“But freshwater increasing is not the only opportunity,” says Jones. “Wastewater also has large potential as a source of nutrients and energy. Recognition of wastewater as a resource, opposed to as ‘waste’, will be the key to driving improved treatment going forward.”

However, the authors stress the importance of proper monitoring of wastewater treatment factories, accompanied by strong legislation (法律) and regulations, to ensure that the reuse of wastewater is safe. The authors also acknowledge public acceptance as another key barrier towards increasing wastewater reuse.

7 . According to the World Food Program, one third of the food of the world is lost or wasted. It’s up to some 1.3 billion tons every year, worth about $1 trillion. Moreover, a report in 2021 Sugests that 8 to10 percent of global greenhouse gas emissions (排放) are associated with wasting food.

“For our parents and the older generations,‘clearing your plate’ is more about saving some food for a rainy day.”Liu Jichen, founder and CEO of Clear Plate, an anti-food wasting program, told us.

The idea for Clear Plate came to Liu after one dinner at a restaurant in late 2017. The customers who finished all the food they’d ordered would be given a card, and then they could exchange their cards for rewards. “Yet it was limited to one restaurant’s actions, so I thought, why not try it on a larger scale (规模)? And how?” Liu wondered. And then he teamed up with some of his friends,founded a startup and developed the Clear Plate applet.

“The Clear Plate team is trying to deal with the issue (问题) of food waste. After a meal, users of WeChat take photos of their clean plates, post these on WeChat, collect points, and then exchange their points for gifts or charity donations,” Liu explained.

Starting in 2018, Clear Plate has now more than 4.3 million users with about 45 million participations in anti-food wasting actions, reducing food waste by 1,700 tons and carbon emissions by 6,600 tons. Liu’s determination represents a small change of the Chinese lifestyle and more people are turning toward a healthier, greener and more low-carbon lifestyle.

Public­square dancing is now very popular with the elderly people in China. In fact, many Chinese ladies, mostly women in their fifties or sixties,     1     (take) up square dancing as a regular form of exercise over the years. Every day after supper, they gather on the square dancing. They think that square dancing is     2     great benefit. Besides helping them keep fit, it also provides them with a good chance     3     (improve) the relationship with neighbors. Also, such dance actually enriches their     4     (culture) life on the whole.

    5    , public­square dancing has also caused some social concerns. The music of square dancing tends to be very noisy,     6     of course disturbs the normal life of people living nearby. Besides,     7     (expose) to such loud noise may do harm to the dancers’ health in the long run.

Square dancing is no doubt     8     good form of exercise and enjoyment, but dancers should take their neighbors’ needs into     9     (consider). They should choose a right time and turn down their music a bit so that they will cause little trouble for others. Only in this way can they dance     10     (happy) and live in harmony with their neighbors.