题目内容：

    Over the centuries, people have created many rituals (仪式) to accompany the consumption of their favourite drinks, tea and coffee. Just think of the Japanese tea ceremony, British afternoon tea or the morning coffee ritual in countless societies. Why are these drinks so popular? 1. In the modern world, the new caffeine delivery systems are canned energy drinks. And the more modern our world gets, the more we seem to need caffeine.

Most people don’t think twice about their caffeine intake. 2. So the widespread use of caffeine is now a cause for concern among scientists and public health authorities. One result of this concern is that you are not allowed to sell energy drinks in France or Denmark. And in other European countries, manufacturers have to label cans with warnings. The United States has no such rule, but many canned energy drinks sold in the USA carry warnings anyway. 3. Studies have shown it helps relieve pain, reduces asthma (哮喘）symptoms and increases reaction speed. Despite this, a study in Ireland recommended that children and pregnant women, among other groups, shouldn’t drink energy drinks.

4. “For most of human existence, the pattern of sleeping and waking has followed sunrise and sunset.” explains Charles Czeisler, a neuroscientist（神经学家） at Harvard Medical School. “Then, the way we work changed from a schedule built around the sun to an indoor job timed by a clock, and consequently humans had to adapt. Electric light, and caffeinated food and drink allowed people to follow a work schedule set by the clock, not by daylight or the natural sleep cycle. 5. Without enough sleep the human body will not function at its best, physically, mentally, or emotionally.”

A. The answer is their secret ingredient --- caffeine.

B. But we need coffee to get us out of bed and back to work.

C. The main reason that people want caffeine is to stay awake.

D. But research suggests that caffeine may have benefits for human health.

E. Nevertheless, there is a heavy price to pay for all this extra wakefulness.

F. However, it raises blood pressure and thus increases the risk of heart disease.

G. Most babies in the developed world are born with traces of caffeine in their bodies.