1 . What is the kindest thing a pet has done for you? My dog gave her life to save my son. Cindy was the most home-loving and smart dog. When my son was born, she was immediately protective over him. She’d sit beside his bed for hours, popping her front legs up onto the bed every now and then to make sure he was OK.

My son was almost three years old. We lived near a busy road and we were super watchful at child going out of the front door—without exception.

One morning, around 4 a.m., our son somehow managed to “escape” through his bedroom window. Cindy knew that our son wasn’t allowed to go through the front door without us, evidenced by her pushing at him if he reached the front door handle. This day, she followed my son through the window.

At 5 a.m. the police woke us knocking on the door. Their words were—“your son was nearly killed but your dog noticed it”. They then recalled what the lorry (卡车) driver had said…

He told them that he was driving along in the dark and in the distance he could see something “light coloured” moving on the road. As he got closer, he could see a dog at the side of the road barking and barking at the “light coloured” something. At the last moment, he realized that this was a child and was about to swerve (转向). He said he could see the dog, still barking and glancing between the lorry and the child. While the driver was stopping the lorry, the dog ran out into the road, jumped at the child’s back and threw him out of the path of the lorry and at the same time, the lorry hit the dog.

The driver said that he’d never believe what he saw unless it was with his own eyes. The dog definitely knew the danger which was why she was barking so anxiously. She just saved that kid’s life and she knew what she was doing.

That was 39 years ago and I still miss Cindy every day. She was a rough collie (牧羊犬) and I can understand why this kind was chosen for the movies.

3 . Ariel Novoplansky, an ecologist in Israel, set up an experiment among pea plants to study how they communicate with each other.

In the experiments Ariel put the pea plants in rows of containers. The center plant in the row was the target. The pea plants had been grown with two main roots. On one side, each pea plant had one root in its own pot and the other reaching into a neighbor’s pot. The central plant connected to its closest neighbor, which connected to another neighbor, and so on down the line. On the other side, all the plants kept their roots in their own pots, unconnected to their neighbors.

With everything ready, the ecologist created a dryness for the central target plant, which had quickly closed up its leaf pores (气孔) to save water. Amazingly, the connected plants on one side gradually closed up their leaf pores, even though only one of them had experienced real dryness. On the other side, with unconnected roots pea chain, all their pores stayed open. This means the warning signal didn’t travel from the stressed plants leaves through the air, but only from its roots through the soil.

It’s possible that plants are just eavesdropping (偷听) even if the damaged plant didn’t mean to send signals to them. Maybe the damaged plant leaks certain chemicals and nearby roots could sense those signals. But the plants with connected roots that weren’t dried out passed on the drought signals to their neighbors too, which means simple eavesdropping probably isn’t the answer. They seem to be having a real conversation, picking up information on one side and sharing it with a neighbor on the other.

The benefit to a plant that receives this information is pretty clear. But what’s the benefit to sending a danger signal to your neighbor? Remember, your neighbor may actually be you.

The Singing Sands Mountain(鸣沙山)is located in Dunhuang in    1     (west)China. Whether you walk through the quicksand    2    slide down a sand mountain, you can hear loud noises from beneath your feet. That’s    3    it is named“The Singing Sands Mountain”. There is a spring lying between the tall sand mountains. This spring, which looks like a crescent moon(月牙),    4    (exist) for thousands of years and has never dried up. The formation and continuous existence of the Crescent Spring are greatly related to its topography (地势).

The flowing water gathers here along the landform and overflows through a porous(可渗透的) geological layer    5    (form) the Crescent Spring. Although its     6    (extreme) dry here, with the annual evaporation being more than 60 times that of the annual precipitation, the stable water source ensures a sustainable water supply to the spring.It’s also due     7    the low-lying terrain(低洼).Whenever there’s a sandstorm, it forms an upward spiral air flow between the surrounding sand mountains, sending the sand at the foot back to    8    top of the sand mountain,and saving the Crescent Spring from    9    (wallow)by quicksand.

The ancient Silk Road once passed by the Crescent Spring. And today, it has become a romantic paradise for    10     (visit).

5 . Giant pandas are among the most lovable animals alive today.     1     So why and how have pandas abandoned their taste for meat to pick up a vegetarian diet?

Pandas today don’t eat meat. However, they’ve kept much of their meat-eating adaptations from times past. Their digestive systems have not changed much from their meat-eating days.     2     Only about 17% of it is digested. To survive, pandas eat large amounts of bamboo while having a low-metabolic (新陈代谢的), lazy lifestyle to make up for the poor energy return.

The giant panda’s shift to a vegetarian diet is in line with the inactivation (失活) of a specific gene—Taslrl, which provides them with the ability to taste certain amino acids (氨基酸) abundant in meat.     3    

Pandas have evolved (进化) to a great degree to cope with their relatively recent bamboo-eating lifestyle. Pandas must seize long and thin pieces of bamboo shoots. To help with this, they have developed a long “fake-thumb” (伪拇指). So giant pandas have six fingers in each paw which provides better support for them to seize objects such as bamboo in one paw quickly.     4     While other bears and many meat-eating animals have smooth tongues, pandas have evolved tiny projections on the surface of their tongues that serve to file down food. This is especially useful for pandas as they remove the outer cover of bamboo.

Time will tell if pandas will adapt and survive, go back to eating meat, or disappear in the wild.     5    

8 . The Greek historian Herodotus is said to have made one of the earliest lists of Seven Wonders of the World. These were man-made structures, including the Hanging Gardens of Babylon. More recent times saw natural alternatives to these wonders of classical architecture proposed: waterfalls, mountains, canyons, reefs. Dramatic landscapes, features and wildlife, and the pleasure and excitement they offer to visitors, are basics of tourism.

As environmental consciousness has risen, attitudes to such sightseeing have changed. Yes, it is exciting to visit remote forests or spot rare species. But travelling to distant destinations is carbon-intensive (碳密集的) when flights or long road journeys are involved, and conservation can be made more difficult as well as assisted by sightseers. There is a balance to be struck, and some governments and businesses around the world try to increase the benefits while reducing the harm. Colombia, for example, recently introduced laws aimed at promoting sustainable tourism. Based on this, its economy got prosperous (繁荣的) as well as the tourism.

Most of us understand better than ever that there are costs as well as benefits associated with exploring. One of the commitments made by an environmental campaign launched last month, “The Jump”, is to “holiday local”, taking short flights once every 3 years and long flights very rarely. Fortunately, the UK’s 15 national parks, 86 areas of outstanding natural beauty, and countless other landscapes that are without formal status, but still beloved, mean that there is no shortage of special places for domestic nature tourists to visit, while a lot of European beauty spots are accessible by rail.

One recent survey found that Windsor Great Park and Kew have become Britain’s most popular attractions. Visitor numbers at wildlife trusts are high, with waiting lists for beaver-spotting. Some companies that formerly ran foreign trips have adapted to the pandemic by taking people to watch dolphins and other marine life off British coasts instead.

As we face an environmental emergency that grows ever more dangerous, it is essential to develop appreciation for nature that surrounds us. In a small way, holiday outings to watch dragonflies, kingfishers or seals, or be surrounded by trees that are coming into leaf, could help us to focus on what matters.

My aim in life is     1     (protect) the environment for future generations. I want to become     2     environmental consultant after graduation. Many people think that pollution cannot     3     (stop) if we want the country to develop. But that is not true. We can cut back on     4     (danger) and dirty waste from factories. Although a factory produces a large quantity of goods, it does not mean that it has to pump a lot of pollution into the environment. I also want to teach people to buy products     5     have been recycled. This is much     6     (good) for the environment, because it means we do not need to cut down many trees.Companies and businesses can still operate,     7     the Earth will not have to suffer.

There is no     8     (debate) that we also have a problem with population. The number of people in the world keeps growing, and we    9     (produce) more rubbish and using up more raw materials. What if they run out? I am confident that if we are all willing     10     (work) together, we can overcome these challenges and keep the Earth clean and healthy.