1 . The world has been troubled by COVID-19 for over a year. Masks (口罩) are really important to everybody during the pandemic (疫情). We all wear masks every day.     1    . This could become a big environmental problem.

In a study, scientists from the US and Denmark said that people around the world are now using 129 billion face masks every month.    2    . What a large number it is!

According to Elvis Genbo Xu from the University of Southern Denmark, disposable (一次性的) masks are plastic products.     3    . People think that they are a new kind of pollution.

    4    . But we can’t recycle masks. Scientists have called for setting up mask-only trash cans (垃圾箱) to deal with mask waste.     5    . We believe that we can solve this problem in the near future though there is still a lot of work to do.

5 . The desert locust (蝗虫) is the most dangerous migratory pest with a huge appetite unmatched in the insect world. In just one day, a swarm of locusts the size of Paris could consume the same amount of food as half the population of France. They annually reproduce, concentrate and then form swarms that can move up to 150 kilometers per day.

To control these swarms, some experts think drone (无人机) technology could provide survey and control teams with an inexpensive and efficient method of searching for these destructive insects.

Unmanned aerial vehicles (UAVs) — also known as drones — could be used to automatically collect high-resolution imagery of green, vegetated areas potentially affected by locusts.

Controlled by a hand-held tablet, the UAV would follow a pre-programmed flight path, covering a 100 kilometer survey radius to collect data. Then the survey teams use the data to identify areas that seem most likely to harbor locusts and travel directly to suspicious locations. Once the team reaches such an area, the UAV could be launched to fly overhead and identify other nearby areas affected by locusts that may require treatment. A separately controlled UAV could then be used to administer pesticides directly onto the locust concentrations. UAVs could also be used to check for locusts in areas that are insecure or cannot be accessed by ground teams.

Pest control operations would become safer, as human operators would no longer be exposed to potentially dangerous pesticides while getting rid of the insects. They would also become more effective, since drones would be able to spray pesticides precisely.

The Food and Agriculture Organization (FAO) of the United Nations is currently working with university researchers and private sector partners in Europe to address challenges of drone technology concerning design, endurance, power, and detection of green vegetation and locusts. The FAO remains hopeful that within five years, UAVs will play an essential role in protecting food supplies and livelihoods from the desert locust, as part of the fight against global hunger and poverty.

7 . Keeping curious kids from disrupting wildlife

Interacting with the wild, naturally curious kids tend to collect seashells at the beach or keep small wildlife as pets.     1     So how to help kids protect the wild while enjoying spending time outsides? Here are alternatives for some of the most common outdoor behavior no-nos.

Take an interest, not things. Kids show interest in picking flowers, rocks, or shells outdoors. They’re part of wildlife's habitat and play an important role.     2     Let kids explore with a magnifying glass (放大镜)instead of their curious fingers. Let whatever they find outside stay outside.

    3     It seems a fun idea to throw pieces of bread to ducks. Animals have unique dietary needs that are different from humans. Eating human food can make them sick or become dependent on human food. Bears are an example of animals that often have to be killed after developing a taste for human food.

Admire animal afar, not disrupt nearby. The urge to take a photo with a squirrel, bird, or slow-moving turtle can be strong for kids.     4     Instead, remind kids to stay away and show them how to use a camera's zoom button, or just admire with their eyes.

Take well-worn paths, not off-road romps (嬉戏). Kicking piles of leaves, stepping on bushes, and walking through forested areas can unintentionally scare wildlife. If surprised animals defend their homes, everyone could get hurt. Nobody likes having a guest come in and destroy their home and act rudely.    5    

8 . More than half the world’s population live in cities, and by 2050 the UN expects that proportion to reach 68%. This means more homes, roads and other infrastructure. In India alone, a city the size of Chicago will have to be developed every year to meet demand for housing. Such a construction increase is a bad sign for dealing with climate change, because making steel and concrete, two of the most common building materials, generates around 8% of the world’s CO2 emissions (排放). If cities are to expand and become greener at the same time, they will have to be made from something else.

Wood is one of the most promising sustainable (可持续的) alternatives to steel and concrete. It is not, however, everyday wood that is attracting the interest of architects.

Rather, it is a material called engineered timber. This is a combination of different layers, each designed to meet the requirements of specific parts such as floors, panels and beams (横梁). Designers can use it to provide levels of strength like steel, in a product that is up to 80% lighter. In addition, engineered timber is usually made into large sections in a factory for future use, which reduces the number of deliveries to a construction site.

According to Michael Ramage of the University of Cambridge, a wooden building produces 75% less CO2 than a steel and concrete one of the same size. However, if building with wood takes off, it does raise concern about there being enough trees to go round. But with sustainably managed forests that should not be a problem, says Dr Ramage. A family-sized apartment requires about 30 cubic metres of timber, and he estimates Europe’s sustainable forests alone grow that amount every seven seconds. Nor is fire a risk, for engineered timber does not burn easily. Besides, fireproofing layers can be added to the timber. All in all, then, it looks as if wood as a building material may get a new lease of life.

9 . Much of the United States is locked by an unusually large winter storm, which has sent temperatures dropping sharply across the country, from coast to coast and as far south as southern Texas. In many areas, ice and snow storms have added to the challenges. Only a few areas in the south have dodged the freezing weather pattern. The National Weather Service( NWS) says that a winter storm, this large and this serious, has almost never been seen before.

The NWS reports that over 150 million Americans were under winter storm warnings. In Texas, over 2.7 million people were left without power on Monday. Texas isn't used to such serious winter weather. In the city of Houston, temperatures have dropped to - 9℃. The storm has led to huge, deadly highway accidents, and has forced its airport to cancel flights. On Sunday, President Joe Biden declared an emergency in Texas, allowing the state to get more help for the weather disaster from the US government. Several other states have declared some sort of weather-related emergency. In Washington and Oregon, warming shelters were opened to help people stay warm and safe.

The NWS says cold air from the Arctic is behind the record-breaking low temperatures. Though it may seem surprising, global warming may be one of the causes. A strong wind known as the jet stream usually flows in a circle around the Arctic, keeping super-cold air near the North Pole. But as the jet stream weakens because of climate change, the cold air is able to escape the Arctic and bring freezing temperatures to places that are normally much warmer.

The NWS is forecasting there’ll be more snow and freezing rain over the next few days as a new storm cuts up toward the Northeast from the middle of the country. The NWS says that much of the country will continue to have extremely cold temperatures, and it's likely that hundreds of cold weather records will be broken. Perhaps, people should think about the consequences of global warming.