3 . More than a score of Australian rare mammals have been killed by wild cats. These predators, which arrived with European settlers, still threaten native wildlife — and are too plentiful on the mainland to eliminate, as has been achieved on some small islands which were previously filled with them. But Alexandra Ross of the University of New South Wales thinks she has come up with a different way to deal with the problem. As she writes in a paper in the Journal of Applied Ecology, she is giving feline (猫科的) — awareness lessons to wild animals involved in re-introduction programs, in order to try to make them cat-conscious.

Many Australian mammals, though not actually extinct, are restricted to fragments of cat-free habitat. This will, however, put the forced migrants back in the sights of the cats that caused the problem in the first place. Training the migrants while they are in captivity, using stuffed models and the sorts of sounds made by cats, has proved expensive and ineffective. Ms Ross therefore wondered whether putting them in large natural enclosures with a scattering of predators might serve as a form of training camp to prepare them for introduction into their new, cat-ridden homes.

She tested this idea on a type of bandicoot (袋狸) that superficially resembles a rabbit. She and her colleagues raised two hundred bandicoots in a huge enclosure that also contained five wild cats. As a control, she raised a nearly identical population in a similar enclosure without the cats. She left the animals to get on with life for two years, which, given that bandicoots breed four times a year and live for around eight years, was a considerable period for them. After some predation (扑食) and probably some learning, she abstracted 21 bandicoots from each enclosure, attached radio transmitters to them and released them into a third enclosure that had ten hungry cats in it. She then monitored what happened next. The outcome was that the training worked. Over the subsequent 40 days, ten of the untrained animals were eaten by cats, but only four of the trained ones. One particular behavioral difference she noticed was that bandicoots brought up in a predator-free environment were much more likely to sleep alone than were those brought up around cats. And when cats are around, sleeping alone is dangerous. How well bandicoots that have undergone this extreme training will survive in the wild remains to be seen. But Ms Ross has at least provided reason for hope.

6 . 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. Such a construction ________ does harm to tackling climate change, though, because making steel and concrete generates around 8% of the world’s carbon-dioxide emissions. If cities are to ________ and become greener at the same time, they will have to be made from something else.

As it happens, Chicago might become part of the ________. In recent years, as architects have become increasingly interested in modern timber (木材) — construction methods, wooden buildings have been getting steadily ________. The current record is held by the 85-metre-tall Mjostarnet building in Norway, completed in 2019. But this would be ________ by the River Beech Tower, a 228-metre building proposed for a site beside the Chicago river.

As the AAAs meeting heard this week, wood is one of the most ________ sustainable alternatives to steel and concrete. It is not, however, everyday wood but a material called engineered timber, composed of different layers for specific purposes. Besides engineering the shape of a component, designers can arrange the grains (纹理) in the layers to provide levels of ________ that equal steel, in a product that is up to 80% lighter. Engineered timber is, ________, usually assembled into large sections of a building in a factory. That cuts down on the number of ________ that have to be made to a construction site.

All this ________ to carbon-dioxide emissions. Michael Ramage of the University of Cambridge told the meeting of a 300-square-metre four-storey wooden building that generated 126 tonnes of CO₂. Had it been made with ________, emissions would have risen to 310 tonnes. If steel had been used, they would have topped 498 tonnes. Indeed, from one point of view, this building might actually be viewed as “carbon ________”. When trees grow, they lock carbon up in their wood — in this case the equivalent of 540 tonnes of CO₂, representing a long-term reduction of CO₂ from the atmosphere.

If building with wood takes off, it does raise concern about there being enough trees to ________. 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 ________ alone grow that amount every seven seconds. Nor is fire a risk, for engineered timber does not burn easily, because the inner cores of large ________ timbers are protected by a charring (炭化) layer if burnt.

Health Warning as UK Swelters

People across the UK have enjoyed the sunshine this week, but they have also been advised to be careful as a heat wave hits much of the country.

A heat wave is defined     1     a period of hot weather where temperatures are higher than is expected for the time of year. They usually happen in summer.

However, climate change (long-term changes to weather patterns, mostly     2     (cause) by human activities such as burning fossil fuels, farming and cutting down forests) is increasing the chance of heat waves happening and making then more extreme. The current hot weather is even     3     (much) extreme in some European countries — temperatures in southern Spain have reached 46℃.

Heat waves can be a danger to people’s health, especially for vulnerable groups such as the elderly, children and people     4     certain health conditions. However, anyone     5     suffer from the effects of extreme heat, including dehydration (not having enough water) and heatstroke (a condition caused by the body overheating). A group of leading UK scientists have recommended that heat waves     6     (name) in order to raise awareness of the health risks.

The Met Office, the UK’s national weather service, has issued an amber warning. Temperatures are expected     7     (rise) to 35℃, and there have been predictions     8     the record for the UK’s hottest day could be broken. Government officials have met to discuss whether to introduce a heat wave emergency.

To cope with hot weather, the NHS (National Health Service) says people should try to keep out of the Sun between 11 am and 3 pm,     9     temperatures are at their highest and the sun is strongest. Make sure you wear a hat,     10     (apply) sunscreen under the sunlight and drink plenty of water. If you are swimming outdoors to cool down, make sure you’re with a trusted adult and follow local safety advice.

9 . Ecotourism is a combination of ecology (the study of systems of living things) and tourism. It is defined as “responsible travel to natural areas that preserves the environment and improves the welfare of the local people” by the International Ecotourism Society. Actually, ecotourism can mean travel to far-off places of great natural beauty, but not always in a(n) _______ way. It's a big business, and the attraction of money can cause people to think about profits first. While ecotourism offers benefits to people and ecosystems, it leaves ecosystems _______ to negative effects, too.

Costa Rica, once a Spanish colony, and independent since 1821, has an ecotourism industry worth over one billion dollars yearly, and thousands of jobs have been _______. Nearly 21 percent of the land is now protected national parks, _______ thanks to ecotourism. Nevertheless, due to the number of people visiting the country's natural places, some damage to the ecosystem has occurred.

While tourists can have a negative impact on ecosystems, the same areas might have been _______ by industries such as farming, logging, or mining if there were no ecotourism industry. Shelters have been created instead, keeping the ecosystem protected. And, by visiting beautiful rain forests and seeing rare animals, visitors get a sense of their _______, and of gratitude for them. Tour guides can also be educators who train people to love and care for the environment. Visitors can take these lessons with them to their home countries.

Unfortunately, while their effect may not be _______ in the off-season, the constant parade of visitors in the high season can be damaging. At one national park in Costa Rica, wild monkeys now feed on garbage left by the tourists. In addition, ecotourists tend to seek out places with the rarest animals and plants, _______ the most delicate living things.

It is easy to be critical of the ecotourism industry, but it is important to be _______ as well. Ecotourism can never be “pure”. We can't expect zero negative effects on the ecosystem. It is also ________ to suppose that humans won't go anywhere accessible to them. If protection efforts are maintained and increased, those remaining places of undisturbed nature may be stressed, but they won't be destroyed.

10 . Biodiversity is a concept that's commonly referenced, yet regularly misunderstood. The complex_______ not only refers to the unbelievable variety of life on Earth, but to how everything from genes to entire ecosystems interact to make the planet habitable. The bad news: science shows that biodiversity is _______ worldwide at a faster rate than at any time in human history. That’s obviously devastating for everything in nature--including us.

“If biodiversity disappears, so do people,” says Dr. Stephen Woodley, field ecologist and bio-diversity expert with the International Union for Conservation of Nature. “We are part of the _______ and we do not exist without it.”

Preventing such a catastrophe, says Woodley, begins with understanding why biodiversity is declining, and then taking action to _______ course.

“The two greatest _______ of biodiversity loss are habitat loss, primarily on land, and overexploitation, primarily in the ocean,” Woodley says. He explains that we can solve these problems by permanently _______ more lands and oceans and managing them for their conservation values.

That's the mission of the global Campaign for Nature, a partnership of the Wyss Foundation and the National Geographic Society. Instead of simply protecting 30 percent of the Earth, the_______ also encourages nations, in full partnership with local communities, to focus on the right 30 percent. Those areas, says Woodley, _______ the most important biodiversity, such as endangered species and ecosystems and rare species and ecosystems.

The campaign also recognizes the importance of_______ local rights. Local peoples manage or hold tenure(保有权) over lands that support about 80 percent of the world's biodiversity, making it ________ for these communities to be full partners in developing and implementing strategies.

________, protecting the health of key biodiversity areas is vital for tackling climate change, says National Geographic Explorer-in-Residence Dr. Enric Sala. Pairing the international Paris Agreement to combat climate change, Sala's paper asserts, “would ________catastrophic(灾难性的) climate change, conserve species, and secure essential ecosystem services.”

“Biodiversity is stability,” says Sala. “Trees, wetlands, grasslands, peat bogs(泥炭沼泽), salt marshes(盐沼), healthy ocean ecosystems, mangroves(红树林), and plants ________ much of the carbon pollution humans put into the atmosphere. Yet, right now, less than half of the planet is in its natural state, which isn't enough.” Bottom line: Nature needs us to act-now. “Moving to Mars is not a(n) ________,” Sala adds. “The only conditions for our life and for the prosperity of human society are here on Earth ...we are ________ protecting it.”