A Battery’s Nightmare
Portable electronics that can be carried about easily are only as good as their batteries (电池) and, let’s face it, batteries aren’t very good, especially when compared with, say, petrol, which packs 100 times a battery’s energy into an equal space. That’s why a large group of mechanical engineers (centered at the Massachusetts Institute of Technology, but with partners at other universities and companies) are hard at work in an effort to replace batteries with a tiny engine that runs on fuel. Imagine a battery-free life! When the fuel runs out in your mobile phone, you just fill up and go.
The engine---about the size of a ten-cent coin---starts with a combustion chamber (燃烧室) that burns hydrogen. Its tiny parts are etched (蚀刻) onto silicon wafers (硅片) in the same manner that computer parts are etched onto integrated circuits (集成电路). The first engine is made up of five wafers. And since these wafers could be produced in much the same way as computer chips, they could probably be produced quite cheaply.
But the devil in all this nice detail is efficiency. Tiny engine parts don’t always behave like the bigger parts of the first engine. Something between the parts can slow down the works, according to Columbia University Professor LucFrechette, one of the engine’s designers. Extreme heat from the combustion chamber is also a problem, often leaking to other parts of the engine.
The scientists’ goal is to create an engine that will operate 10 times better than batteries operate. Frechette says that a complete system, with all parts in place and working, will be set up in the next couple of years, but commercial models aren’t likely until at least the end of the next ten years.
【小题1】According to the passage, the title suggests that _______ .
| A.batteries should be greatly improved |
| B.petrol will be used instead of batteries |
| C.the time of batteries will be gone forever |
| D.pollution problems caused by batteries must be solved |
| A.Problem | B.Advantage | C.Invention | D.Technique |
| A.The new invention doesn’t need any fuel. |
| B.The new engine has been produced in large quantities. |
| C.The new invention is much cheaper than the battery. |
| D.The new engine needs to be improved before it’s on sale. |
The United Nations says forty million people or so around the world went hungry in 2008, mainly because of higher food prices. Early estimates from the UN Food and Agriculture Organization (FAO) show that 963 million people did not get enough to eat.
World food prices have dropped since early 2008. Prices of major crops have decreased by more than half from their height earlier last year. But they remain high compared to earlier years.
But FAO official Hafez Ghanem says lower prices have failed to end the food crisis (危机) in many poor countries. “For millions in developing countries,” he says, “getting enough food every day to live an active and healthy life is a distant dream. ”
The FAO says food shortage is a threat to people's health. Today, two-thirds of the world's undernourished people live in just a few countries. These are India, the Democratic Republic of Congo, Bangladesh, Indonesia, Pakistan, Ethiopia and so on.
A report on food insecurity warns that the current economic crisis could send even more people into hunger and poverty.
In sub-Saharan Africa, the percentage of the people who continually go hungry fell from 34% in 1997 to 30% in 2008. But the FAO says Ghana is the only country that has reached two sets of hunger reduction targets. These were set by the 1996 World Food Summit and the Millennium Development Goals. The main reason is the growth in agricultural production in Ghana.![]()
![]()
The FAO says some countries in Southeast Asia like Thailand and Vietnam have made progress in hunger reduction goals. But South Asia and Central Asia haven't, and North Korea is still in hot water.
【小题1】What FAO official Hafez Ghanem says implies(暗示)__________
| A.it's easy but takes long to provide people with enough food |
| B.enough food can make people more active and healthier |
| C.there is difficulty solving the food shortage in a short time |
| D.people in developing countries will never get enough food |
| A.hungry and unhappy | B.unhealthy for lack of food |
| C.not fat because of poverty | D.undeveloped and poor |
| A.The food production of the world |
| B.The hunger reduction target of the FAO |
| C.The food shortage around the world |
| D.The solution to the global food shortage |