Getting older

No one really knows how and why people change as they get older.【小题1】Aging is a complex and varied process that varies in how it affects different people and organs. In fact, even in one person, different organ systems “age” at different rates.

At a certain point in our lives our body systems will begin to weaken.【小题2】.It may become more difficult for us to see and hear. The slow change of aging causes our bodies to lose some of their ability to bounce back from disease and injury. In order to live longer, we have always tried to slow or stop this change that leads us toward the end of our lives.

【小题3】. A good diet plays an important role. The amount and the type of exercise we get are another two factors. 【小题4】. But scientists studying the aging problem want to know: why do people grow old? They hope that by studying the aging medical science they may be able to make the length of life longer.

【小题5】. Many consider the later part of life to be the best time for living. Physical activity may become less, but often we get better understanding of the world and ourselves.

What we consider the old age now may only be middle-aged some day soon. With so many advances in medical science happening so quickly, life length may one day be measured in centuries, rather than in years!

Seasonality is a big part of business. For some industries, seasonal patterns are a defining feature. Agriculture is one obvious example; tourism another. Western toymakers notch up a huge proportion of their annual sales during Christmas. Construction is harder during cold weather, when that industry employs fewer people.

Firms less obviously tied to the seasons can still be deeply affected by them, as a recent review by Ian Hohm of the University of British Columbia makes clear. An analysis of social-media posts on the Internet found that dieting-related posts peak in the spring, as the season of body dysmorphia (变形) approaches.

Even when overall demand doesn’t vary greatly between the seasons, preterences change. Beef-eaters buy roasts in the slow-cooking winter season and plump for steaks during the summer months. Starbucks is among those firms that make seasonality a marketing event. The pumpkin-spiced latte is a reliable sign that autumn is on its way, along with falling leaves.

Seasonality also leaves a less obvious imprint (印记) inside organisations. This week, with so many bosses stuck on a mountain for the World Economic Forum’s annual meeting in Davos, productive employees can get on with some work and lazy ones can relax. School holidays offer an obvious form of seasonality, when employees without children are upset that they are covering for colleagues on holiday, and colleagues on holiday are upset that they have children.

Pay decisions are seasonal events, too. The time when employees find out their salary rises and bonuses sets off disappointment and happiness in all workplaces. In some, they are more like tsunamis. The actual date on which bonuses are paid matters too — once the money is safely put in the bank, people are more likely to move jobs.

There are other forms of corporate seasonality. While there isn’t much research on the impact of seasonality within firms, it’s certain that they have their own annual rhythms.

Sales of electric vehicles（EVs）grew by 40 percent last year worldwide. In the US, nearly a third of drivers want their next car to be electric. Almost 100 pure-electric vehicles are set to be launched by the end of 2024. Many manufacturers, including GM, Jeep, and Volvo, have promised to offer fully electric lists before this decade is done.

Though some EVs are still eye-wateringly expensive, plenty of other EVs are even more affordable. When assessing the cost of an EV, keep in mind that many states offer additional buying payment if you're switching to an electric vehicle. Some models will even qualify you for a federal tax credit of up to $7,500. Then there are the long-term savings. A typical EV owner spends less than a traditional car owner on vehicle services. One reason is that EVs don't have transmissions or clutches, two of the costliest parts to repair.

EVs go without the classic vroom（加速时发出的呜呜声）we expect to hear when we floor it. That quietness can catch pedestrians off guard and strikes some drivers as terrible. That's why several electric automakers have turned to sound designers to copy these desired engine noises.

You can run an electric car through a car wash without worry. The water will not damage any of the electrical components or the battery because these systems are specially sealed to prevent water entry. What you do need to watch out for, however, is extreme cold or heat. Both will affect the battery and reduce an EV's range.

While EVs produce far fewer emissions than conventional cars do, they aren't without environmental influence. Coal is still burned to create the electricity that charges them. And EV production is emission intensive（密集排放型）. So power systems need to become carbon-free and EV batteries need to fully become recyclable before EVs can be truly emission-free.