Imagine a perfect day: the weather is good and everything seems fine. When, suddenly, your mobile phone loses its signal, the television has no programs, and you can’t get online with your computer. What has happened? These are just the types of problems a solar storm (太阳风暴) might cause. You may not think of storms as putting our society in danger. But today, a solar storm is as serious as other bad events, such as earthquakes.

A solar storm is caused by solar flares (太阳耀斑): large explosions (爆炸) near the sun that can give of lots of energy. The strong energy can stop the satellite systems (卫星系统) that control our computer, telecomputer networks and so on. These storms can even cause the power to go out for weeks or months.

In the past few months, scientists have recorded some of the strongest sun flares in years. The most recent one happened around Valentine's Day, 2011. It caused radio and satellite signals to go down in some northern cities in China.

“Solar flare activity is going to be much worse than what we’ve seen in the past. We’re not talking about a few cities losing power, it could be half of the country, maybe more,” a US website about space weather, warned.

Scientists say that little can be done to predict such a storm. Governments around the world are trying to work together before the next storm, although they are not sure when that may happen.

Do you think there is too much noise in our city? Perhaps you do. If you live near an airport, you will probably feel unhappy because of the noise of planes. It is said that the noise of planes or trains or trucks can make one deaf if he keeps on hearing it.

Noise is a kind of pollution. However, most people in our city do not seem to mind noise. They do not know it is harmful to their health. They like to enjoy music when they are doing their work. It is a new danger that music is played through powerful loudspeakers (声音大的喇叭). It can reach 120 decibels (分贝).

It is known that continuous (连续不断的) noise of over 85 decibels can make people deaf. For example, when newspapers and books are being printed, the noise is over 85 decibels, and some of the workers become deaf. Scientists believe that 10 percent of all the workers in British printing offices have been deafened (使……聋) by the noise. Besides, noise of less than 85 decibels can make some people tired and nervous. We all know that too much noise makes life difficult and unpleasant. It can do great harm to health and prevent people from working well. Workers in noisy offices are not so efficient as workers in quiet offices. Noise makes people less efficient. Can anything be done to keep down noise?

In Britain, the government has made several laws to keep down noise. It has spent a good deal of money making airports and main roads quieter. In Japan, America and Canada there are such laws too.

Recently Chinese researchers have described what they claim is the world’s youngest Alzheimer’s (阿尔茨海默症) patient, a 19-year-old boy in Beijing, as an “interesting” discovery that could help know the development of the disease that mostly affects the elderly.

The youngest patient first experienced difficulties paying his attention to study when he was 17 and began to have trouble remembering little or even more important things, such as being unable to remember the events two days ago or where he’d left personal belongings, according to a study published in the Journal of Alzheimer’s Disease, an international peer-reviewed journal, on January 31.

The study found that the patient’s memory continued to get worse, and he often misplaced items and even had trouble remembering whether he had eaten. He dropped out of school because of his condition, but was still able to live on his own.

Since the first case of AD (Alzheimer’s disease) was reported in 1906, it has been widely believed that AD mainly happens in the elderly according to the researches since then, AD is a chronic neurodegenerative disease (慢性神经退行性疾病) with slow onset (发病) and loss of cognition (认知) little by little, memory and speech and an increase in mental disorders over time, eventually leading to inability to take care of oneself. It is currently difficult to treat the disease.

There are two types of AD, familial (家族性的) and sporadic (散发性的), Peng Dantao, chief physician of the China-Japan Friendship Hospital told the Global Times.

About 15 percent of AD patients have the familial type and the age of onset is generally when people are in their 20s or 30s. Most AD cases are sporadic, and it is most common in people over 65. It affects about a fifth of those over 80, Peng said. And this case of the 19-year-old boy shows patients who suffer from the disease are becoming even younger than we think.