2 . Diving made my world bigger.     1     It took me three years and three tries to get certified, but I’m glad I persisted.

Learning to dive is a lot like learning to drive a car: You study the theory, practice with an instructor, and become qualified. From there, proficiency (熟练) depends on how often you dive, further training, and your own self-reliance. Regardless of your goals, diving is more accessible and wondrous than I ever imagined.     2    

But not everyone wants to or can dive, and that’s fair enough. Whether you’re a snorkeler (潜水员), surfer, or sailor or you simply enjoy dipping your toes into the sea while on holiday, you can still be aware of the life unfolding under that glittering blue cover and help protect it.

    3     Experts urge that at least 30 percent be protected to safeguard marine ecosystems, which in turn will help protect our health and well-being. The ocean supplies more than half our oxygen, absorbs carbon dioxide, regulates our climate, and supports much of the world’s economy. We need it a lot more than it needs us.

Take Florida, for example, it’s bordered by North America’s only living coral barrier reef (礁石) and the third largest in the world.     4     It is also essential to its economy, generating an estimated $1.1 billion annually in tourism. The reef protects the coastline, too, since healthy coral reefs absorb 97 percent of a wave’s energy.

A study has found that 70 percent of Florida’s coral reefs are experiencing a net loss of reef habitat. Exactly facing these concerns is what I mean by seeing the sea — the good, the bad, the important.     5     We can use it to inform our choices, from traveling more carefully, to examining how we run our businesses. No one can do everything, but everyone can do something. The ocean is a remarkable teacher, and it’s never too late to start learning.

Care Needed for Great Wall’s Preservation

Although the Huanghuacheng section of the Great Wall in Huairou, Beijing, was     1    as a key heritage site under state protection as early as March 2013, for years, local villagers have     2    it to a cash cow to collect “entrance fees” and “guide fees” from sightseers without the permission of the cultural relics and tourism authorities.

As long as the fee is     3    , tourists are allowed to climb the mountains along whose ridges the Great Wall meanders. The damages inflicted by the villagers’ “business” upon the Great Wall, which was     4    in the 15th century during the Ming Dynasty (1368 —1644), are self-evident. It is not rare for tourists to bring     5    bricks from the already run — down wall as a souvenir or to carve their names on the wall.

How can the local watchdogs of the tourism industry and the cultural relics protection departments sit back with folded arms ignoring the practice for such a long time is a question that still awaits an answer.

Reportedly, some of the money the villagers     6    finds its way into the pockets of those who are legally bound to protect the Great Wall. That’s why the villagers have become so assured and bold that they claim as natives to the area at the foot of the Great Wall, they are naturally entitled to profit from it, as if the Great Wall is their private property.

Unlike the Badaling section of the Great Wall in Yanqing, Beijing, which is     7    good care of as a showpiece of the nation’s historical heritage, most parts of the Great Wall have been weather — worn over the years without repair since the Manchurians from the north put an end to the rule of the Ming Dynasty, making the once important national defense project nothing but a wall running through the middle of the large Qing Empire.

Nearly one-third of the Great Wall built in the Ming Dynasty has     8    because of weathering and human causes over the past 300 years. Not to mention the parts that had been built before that.

With the Beidou satellite global navigation system in place and the advancement of technologies in other fields related to the protection of cultural heritage, the country is now better able to protect the Great Wall. But unless the malpractice of the grassroots authorities is addressed, no technology will be of practical assistance in     9    this historical legacy for future generations.

The Great Wall’s     10    length and magnificence are not reasons for its being left untended, but exactly why it should be well preserved.

6 . When Purdue University researchers set out to develop a new paint, the goal was to create one that would reflect sunlight away from a building. It turns out they also set an official Guinness world record for the whitest paint on the planet.

“When we started this project about seven years ago, we had saving energy and fighting climate change in mind,” Professor Xiulin Ruan said.

The paint reflects 98.1% of solar radiation while also emitting infrared (红外线的) heat.

Because the paint absorbs less heat from the sun than it emits, a surface coated with this paint is cooled below the surrounding temperature without consuming power. Typical commercial white paint gets warmer rather than cooler, Paints on the market that are designed to reject heat reflect only 80%-90% of sunlight and can’t make surfaces cooler than their surroundings.

“Conventional air conditioners consume power that is often from burning fossil fuel. Meanwhile, while they move the heat from inside of a house to the outside, they turn the electricity into heat and leave even more heat to the surrounding and earth, further causing a heat island effect and warming up the Earth,” Professor Ruan told IFLScience.

“In contrast, our paint does not consume any power, and directly sends off all the heat to the deep space, thus helping cooling down the Earth. According to a previous model, painting 0.5-1% of the Earth’s surface (roofs, roads, cars, unused land, etc) with our paint will stop the warming trend. Painting many human made-structures would be a great way to fight the climate crisis in many ways. The paint is not yet available commercially and the scientists are working with a commercial company to speed up the paint production and put it on the market.

8 . Wild beavers (河狸) are back! Experts say that the wild beaver families are doing well. The beavers are even boosting wildlife and the environment!

Over ten years ago, a family of beavers turned up in a part of the river Otter, in Devon. No one knew exactly where they came from. It was a big surprise wild beavers hadn’t lived in England for around 400 years!

In 2015, the government allowed the beavers to stay there as part of a test. They wanted to see if these animals could be reintroduced to the wild. The test ends in February. Some scientists from the University of Exeter already say the beavers help the wildlife in the area. One scientist called it “an amazing story”.

A lot of this is because of dams (水坝). Beavers build dams along the river. This creates deep pools in the riverbed and slows the water down. Scientists say this is perfect for many different types of plants and animals! Many plants are growing near the beavers. Different types of animals are also becoming more and more in the river. Beavers also help make flooding less, scientists say. The beavers’ dams slow down the speed of the river, especially after heavy rain.

Beavers aren’t the only animals that are being reintroduced to the wild! In 2019, red squirrels were brought back to an area of the Scottish Highlands. Further away, the world's rarest (罕见的) duck, the Madagascar pochard, is making a comeback. It was set free into the wild on the African island in 2019 and is doing well.

Who knows what other animals might be making a comeback?

We require healthy water and air, and so do we require healthy soil. It makes water clean and serves as a growing medium, It provides a living space for billions of organisms. And it also provides us with food. Therefore, we should do something to protect the soil.

    1    

One of the easiest ways we can support the soil is by wasting less food. All the food that ends up in our shopping bags requires land, water and energy to produce. By throwing away less, we will prevent materials in soil from being wasted.

    2    

By eating different types of foods, we can help create demands for different farming products, which is better for soil. Food diversity can improve soil quality. In general, eating a diverse (多样的) diet is better for our health too.

Read the instructions on garden products.

When we walk through any garden store, there are many products for our gardens. No matter which product we end up selecting, the most important step before using it is to read the instructions, Misuse can cause problems.

    3    

If we are looking to fertilize (施肥) our garden，we need to know what materials are already in the soil before adding more. Or, we might just need to add one specific material, and not others. Local university laboratories can help provide information on testing soil. It’s usually a matter of digging up soil from a few areas of the yard and sending it in to the lab!

10 . All living things on Earth need water to live. Yet humans are facing serious water problems. According to the United Nations, today over 663 million people live without a safe water supply close to home.

To remind people of the importance of water, the UN first set up World Water Day in 1993. It is on Mar 22 each year. From Mar 22 to 28 is also the China Water Week. The first year’s theme is “Waste water”. It tried to call people to reuse waste water instead of wasting it.

In Australia people make good use of waste water. Most Australians have a grass lawn around their home instead of washing the car in the street. Many of them wash it on the lawn to keep the grass longer so that it covers the ground and reduce evaporation.

Rainwater may seem useless to you. But you can also reuse it. People in Germany collect rainwater to wash their toilets. Most houses in the country that are built in the last few years have rainwater collection devices (设备). Rainwater is collected from the root, and then linked to the toilet. But if you don’t have the device just put a bucket (桶) under your roof when it rains.

Water makes up 71 percent of Earth’s surface. But we can only use a very small part of it. Only about 3 percent of the world’s water is fresh water. It’s in lakes, rivers and underground.

Over 80 percent of the waste water in the world goes back into the nature. It has not been cleaned and pollutes the rivers and lakes. Unsafe water makes around 842,000 people die each year.

By 2030, about half of the world’s population could be facing water problem. By 2050, as many as seven billion people across the world could not have enough water supplies. The world’s population might be 9.3 billion by then.