1 . Julie Willis is an artist from San Francisco who moved to London ten years ago. We asked her to compare life in San Francisco and London. Here’s what she told us.

San Francisco is a lovely city in a beautiful bay in the USA. It’s got lots of great buildings and places. It’s smaller and much more modern than London, but it’s less interesting. London has a lot more theatres and museums. The Americans are usually more interested in money than culture! The buildings and streets in London are very great, and the parks and markets are wonderful. London is not as dangerous as San Francisco. I feel much safer living here—nobody carries a gun. The police don’t carry guns either.

(2) The living

People have a higher standard (水平) of living in San Francisco because it’s much less expensive than England. For example, petrol is less than half the price and the things like food, clothes and cameras are much cheaper. It’s a shopper’s paradise and I always spend a lot of money buying things before I go back to London! It’s a bit more expensive to rent a house in London and my bills are much bigger than they were in San Francisco. So, although my salary in London is about the same as it was in the United States, I have to work harder to get the same quality of life as I had before.

(3)________

In San Francisco you can walk everywhere because it’s a small city. There’s less traffic than in London, and the public transport is great. There are cable cars to go up all the hills and electric buses which make the city much cleaner. Public transport in London is terrible and really expensive. It takes me an hour to get to work and the journey is usually stressful (紧张的). London’s dirtier too and much more polluted. The traffic is bad, because there is too many cars and the streets are narrow. But English drivers aren’t as bad as American drivers.

(4) Food

Food in the United States is much better. It’s fresher, cheaper, and there’s much more choice. Restaurants aren’t as expensive as in London and the service is much better. In some restaurants they put a clock on the table when you arrive, and if they haven’t served your meal in five minutes, they’ll give you the food free!

3 . A very important world problem is the increasing number of people who actually inhabit this planet. The limited amount of land and land resources will soon be unable to support the huge population if it continues to grow at its present rate.

So why is this huge increase in population taking place? It is really due to the spread of the knowledge and practice of what is becoming known as “Death Control”. You have no doubt heard of the term “Birth Control”. “Death Control” is something rather different. It recognizes the work of the doctors and scientists who now keep alive people who, not very long ago, would have died of a variety of then incurable diseases. Through a wide variety of technological innovations that include farming methods and the control of deadly diseases, we have found ways to reduce the rate at which we die. However, this success is the very cause of the greatest threat to mankind.

If we examine the amount of land available for this ever-increasing population, we begin to see the problem. If everyone on the planet had an equal share of land, we would each have about 50,000 square metres. This figure seems to be quite encouraging until we examine the type of land we would have. More than three-fifths of the world’s land cannot produce food.

Obviously, with so little land to support us, we should be taking great care not to reduce it further. But we are not! Instead, we are consuming its “capital”—its nonrenewable fossil fuels and other mineral deposits that took millions of years to form but which are now being destroyed in decades. We are also doing the same with other vital resources not usually thought of as being nonrenewable such as fertile soils, groundwater and the millions of other species that share the earth with us.

It is a very common belief that the problems of the population explosion are caused mainly by poor people living in poor countries who do not know enough to limit their reproduction. This is not true. The actual number of people in an area is not as important as the effect they have on nature. Developing countries do have an effect on their environment, but it is the populations of richer countries that have a far greater impact on the earth as a whole.

4 . Inadequate drinking water and sanitation, indoor air pollution and poor living conditions, and accidents injuries and poisonings: these are just three of the causes of the nearly 3 million deaths suffered every year by children under age five due to environmental dangers.

1.3 million children under five in developing countries died from diseases caused by unsafe water supply, sanitation and hygiene each year. According to a publication by WHO, 60% of the 2.2 million deaths a year in children under five caused by acute respiratory infections (急性呼吸道感染) are associated with indoor air pollution, the lack of adequate heating and/or other unhealthy living conditions. Accidental injuries—including road traffic accidents, drowning, burns and poisonings—are the cause of over 400,000 deaths per year in children under five.

Yet, until recently, no specific efforts had been made to deal with the environmental dangers which specifically affect children. Children are not “little adults”: they are in a constant process of growth and development, and they are easily affected by the harmful substances in their environments.

Research suggests that over 40% of the global burden of disease due to environmental risk factors may fall on children under five, even though they make up about 10% of the world’s population. The WHO will focus on the main environmental threats to children’s health and development, and on a range of measures to reduce environmental impacts on children as well as children’s exposure to lead, mercury, poisons and other chemicals.

In Bangladesh and India, for example, arsenic (砷) in drinking water is a lasting problem. In some countries, concern exists about exposure to lead and any by exposure to waste sites. WHO plans on launching pilot projects to help countries assess (评估) and improve children’s environmental health in the near future.

The environment if places besides the home—above all schools, and workplaces—can be made safer for children. Schools are of particular significance, as a healthy and safe school environment can help protect children from health danger, abuse and exclusion and can foster learning.

“A commitment to child health means that dangers should be reduced in all places where children spend significant parts of their day, including the roads and forms of transport they use to get to and from these places,” said an official of WHO’s Department responsible for Environmental Health.

5 . Some wonderfully creative uses of X-rays have been in the world of art. But the most impressive one is to uncover what has been covered up. Details unfolded by an X-ray of a painting can’t be seen any other way. For example, in the past, paintings were often repaired if small pieces of paint fell off the canvas (帆布). These repairs cannot be seen just by looking at the painting. It takes an X-ray to discover where the repairs have been made.

An X-ray of a painting is one of the best ways to tell if it was created by a famous painter or if it is a forgery (赝品). If there is a question as to whether an old master has painted a certain painting or not, X-rays are made and compared to those of paintings that are known to be original. If the brushstrokes (笔迹), for example, are shown to be totally different than in other work done by a certain artist, then the painting is proved to be a fake copy.

Since modern paints are usually made from different materials than paints of hundreds of years ago, the image they leave on an X-ray film looks different. This is another way X-rays can be used to spot a forgery. A modern artist will try to make a forgery look hundreds of years old by painting dirty varnish on it or by using artificial means to get the varnish to look cracked. To the naked eye the forgery may look old, but when a careful study of the X-ray image is made, the deceptions obvious.

It was common many years ago for an artist to finish a painting, decide it wasn’t any good, and paint a completely different picture on top of it. Or artists would paint over others’ work —it was their version of recycling. Taking an X-ray is the only way to find out if there is a picture underneath the picture you see with your eyes. Sometimes museums will be more interested in the painting beneath than the one on top, and will restore the older one by having the top layer painstakingly removed.

7 . Warming temperatures and shorter winters might sound like the end of snow days. However, rising temperatures may actually cause snowstorms to dump more snow, says David Robinson. He is a professor at a university in New Jersey. He studies climate (气候) change.

Temperature change is one of the greatest in Earth’s climate change over a long period of time. It can happen naturally or because of human activities, such as burning gas and coal. Burning these fuels produces carbon dioxide (二氧化碳) and other pollutants into the atmosphere, which hold heat in the atmosphere, leading to warmer global temperatures over time.

But how could warmer temperatures lead to more snow? To get snow, you need moisture (水汽) and freezing temperatures (0℃ or less), says Robinson. Without moisture in the air, there is no precipitation (rain or snow). Robinson says there are signs that snowstorms are becoming stronger. This is because of this connection between moisture and precipitation.

“The warmer the air becomes, the more moisture it holds. So, if it’s warming and still cold enough to snow, you can get more snow,” Robinson says.

Of the 10 biggest snowfalls in D. C. region, five happened in the past 25 years, according to the NWS. During that same time period, average winter temperatures in D. C. increased. In 1996, the average winter temperature was 1.8℃. In 2020, it was 6℃.

Weather experts suggest that rising temperatures may make winter shorter and less cold. But for now, the snow is still falling. One day, winter might not have any days below the freezing temperature. Once temperatures stay above freezing, snowstorms become rain. Until then, we might continue to see strong storms.

According to Robinson, that time could come sooner than we think. He says, “When we look back, years from now, we may see that this was the breaking point.”

10 . There are a couple of ways to forecast the destructive potential of a hurricane (飓风) so that people in the way can take adequate precautions (预防措施). Satellite images of cloud patterns can be analyzed to estimate peak wind speeds, but the estimates are often way off the mark. Specialized aircraft can fly into a storm to measure the winds directly, but the flights are costly.

Researchers at the Massachusetts Institute of Technology come up with a third way: listening to a storm underwater.

In a paper to be published in Geophysical Research Letters, Nicholas C. Makris and a former graduate student, Joshua D. Wilson, report a strong connection between the intensity (强度) of sound recorded by an undersea microphone in the mid-Atlantic and the wind power of a hurricane that passed over it. They say that such microphones, known as hydrophones, could be a safe and relatively inexpensive means of estimating hurricane force.

Dr. Makris and Dr. Wilson, who are now with Applied Physical Sciences Corporation, worked out the theory of underwater acoustic (声音的) monitoring of storms in a 2005 paper. “To be very frank with you, it’s a mystery what makes storms noisy underwater.” Dr. Makris said. The most popular idea currently is that it has something to do with oscillating air bubbles(气泡振动).

The researchers then went looking for experimental data to back their theory, and found it from a hydrophone placed at a depth of 2, 500 feet by the National Atmospheric and Oceanic Administration. It happened that Hurricane Gert passed over the area in September 1999, and a hurricane-hunter plane directly measured the wind speed at the same time. The hydrophone data showed sound intensity rising when the storm’s outside wind “wall” passed over, and again when the inside wall, the most destructive part of the storm near the eye, passed over. “We got a beautiful connection,” Dr. Makris said, “between the hydrophone data and the actual wind speeds as measured by the aircraft.”

Dr. Makris is conducting additional experiments, working with the Mexican Navy off the west coast of Mexico. The eventual goal, he said, would be permanent hydrophones in known hurricane zones or temporary ones that could be easily laid by plane or ship in the path of a coming storm.