The unbearable winter coldness couldn't stop their steps. With【小题1】(curious) and excitement, villagers at the foot of Mount Qomolangma hurry up to open their parcels at a delivery office. At an altitude of 4119 meters, this is the world's【小题2】(high) delivery service station.【小题3】(locate) in the town of Tashi Dzom in Tibet, the delivery office【小题4】(found) in 2016. Before that, local people had to spend around four hours to collect parcels from the county seat. But the delivery office brings great【小题5】(convenient) and therefore encourages more people to order online. According to Yang Tao,【小题6】is a worker at the delivery office, the office handled only 17 parcels in its first month. But thanks【小题7】the fast-growing industry, the number has grown steadily to【小题8】average of 200 per month. Not only has the number of parcels increased,【小题9】also the items being delivered have become richer in variety. Though people in China's eastern regions may take【小题10】for granted, the delivery office indeed makes a difference to the local people.

Commercial airlines alone contribute around three percent of total global carbon emissions. But the industry is【小题1】(active) looking for green solutions in the form of sustainable airline fuel which【小题2】(believe) to have had a previous life as your household food waste. In a study【小题3】(release) this week in the Proceedings of the National Academy of Sciences, researchers detail a method of transforming food waste into sustainable airline fuel.

Biomass, such as animal and food waste, can be transformed into biofuels,【小题4】are renewable liquid fuels made from organic matter. Derek Vardon, a senior research engineer at the National Renewable Energy Laboratory (NREL), says that their fuel worked as a mixture of 90 percent conventional petrol airline fuel and 10 percent alternative airline fuel required by the industry currently. They also show they could push it to a 70/30 mixture【小题5】 more time and testing available.

Major companies are eager to participate in sustainable airline fuel【小题6】some sustainable solutions, such as battery-operated commercial planes, just aren’t possible yet with current battery technology. 【小题7】battery-powered plane would be too heavy to fly long distances, so fuel that works in the same way as the fuel we have is a simpler way to trade out emission-heavy fossil fuels.

Vardon says that because the wet waste used in the process would normally go to a landfill (垃圾填埋场) and break down to release greenhouse 【小题8】(gas), the process of making and using sustainable airline fuel could actually have a negative carbon footprint when scaled up.

Commercial airlines are also on board to find an【小题9】(afford) and sustainable solution to the carbon-intensive process of air travel. Airlines are looking to hit aggressive sustainability goals by 2050, including【小题10】(decrease) net carbon dioxide emissions by 50 percent.

China’s first overpass for wildlife migration has already come into use. Lying over the 【小题1】 (new) constructed National Highway 216, the bridge is able to link animal habitats 【小题2】 (separate) by the road.

The national highway 【小题3】 (design) with the environmental protection as a top priority. Based on years of 【小题4】 (science) observation of wildlife migration in the region, the bridge was built with the purpose of reducing the highway’s effect 【小题5】 the animals. The wildlife overpasses and underpasses let animals 【小题6】 (cross) over or under busy roadways safely and allow them to use 【小题7】 (they)customary paths, which would otherwise be blocked. Those passageways, with 【小题8】 total length of 59 kilometers, enable antelopes and other animals to go across the railway freely.

So far, China 【小题9】 (put) great effort into achieving harmonious coexistence between human development and the protection of wildlife. The Qinghai—Tibet Railway, 【小题10】 is the world’s highest railroad, has 33 underpasses for the migrating animals.