Your brain controls everything you do. It makes it possible for you to think, learn, create and feel; to blink(眨眼) and breathe and for your heart to heat—this fantastic control center is your brain. It is so amazing that a famous scientist once called it "the most complex(复杂) thing we have yet discovered in our universe".

Can this small grey organ(器官), which weighs less than one and a half kilos, really do so much? Amazingly, your brain contains about 100 billion neurons(神经元)—it would take you over 3,000 years to count them all. Believe it or not, the activity in your brain never stops. Your neurons create and send more messages than all the phones in the world. And although one neuron creates only a little electricity, all your neurons together can produce enough electricity to power a light bulb (灯泡).

So exactly how fast does your brain work? Well, imagine this: a bee lands on your foot. Neurons in your skin send this information to your brain at a speed of more than 240 kilometers per hour. Your brain then uses other neurons to send the message back to your foot to shake the bee off quickly. These neurons can send this information at more than 320 kilometers per hour. No computer has your brain's unbelievable ability to deal with the amount of information coming from your eyes, ears and other sensory organs.

But how does your brain allow you to learn things that you will use in the future? The structure (结构) of your brain changes every time you have a new thought, remember or learn something. For example, riding a bike seems impossible at first, but soon you are able to do it. How? As you practice, your brain sends "bike riding" messages again and again. Soon, the actions are learnt and you are able to ride a bike easily from then on.

CHINA has built a biscuit factory to make food for its captive (圈养的) giant pandas, giving them a healthier diet (日常食物) than the usual steamed bread.

The special biscuits, developed by the Chengdu Giant Panda Breeding and Research Centre, are shaped like bamboo so they will not seem unfamiliar to the pandas.

"The cream-colored biscuit, made of bamboo, is rich in vitamins and has 30 per cent more fiber (纤维) than normal bamboo," said Yu Jianqiu, who is in charge of the project.

Steamed bread, which is eaten by most captive giant pandas as well as fresh bamboo, loses much of its goodness when cooked, often causing bad health. What's more, it can only be stored for a short time, making pandas expensive to feed.

Thirty pandas have tried the biscuits since the factory was completed in October.

"They love our new biscuits," Yu said. "In time, all captive pandas will be given the new food."

Around 1,000 giant pandas live in the foggy mountains around the Sichuan basin (盆地) in southwest China, while about 140 live in captivity around the world.

The destruction of forests, a panda's natural home and major food source, is the biggest threat to the animal.

In 1998, China banned the cutting down of trees in panda-inhabited areas to help save an animal seen as a national treasure.

The idea of “time banks” was created by Yale University Professor Edgar Cahn in 1980 as a way to encourage voluntary work. It’s simple enough. People who volunteer to help others in their communities get “time dollars” or “time coins”—that can be exchanged in later life if they need help. It has taken effect in Britain, Japan, Sweden and other countries. And so, too, in China.

The idea of “time banks” was introduced in China in the 1990s, and Shanghai was one of its first users. However, being short of clear rules, volunteers and good-management, the project finally failed. Recently, the idea has become popular once more because of China’s rapidly aging population.

The Chinese version mostly hopes to encourage younger senior people to provide services for the older ones. I’m happy to help them before I become too old to look after myself, said Yang Beifen, 68, a community volunteer in Shanghai. I’ve collected over 10 coins now, and it’s comforting to know that I can use them if I need to in the future.

The idea of “time banks” is one way to deal with the problem of an aging population. By the end of last year, there were more than 5.2 million people aged 60 or older in Shanghai. Of these people, about 30 percent were aged below 64 and 16 percent were over 80. Many young people are too busy to care for the elderly, so the elderly have to help each other. The Bank of China even developed a WeChat mini program to help the elderly.

However, the needs of the elderly are a great challenge for the city. There’s a long way to go.