试题详情

共用题干 第三篇

Renewable Energy Sources

Today petroleum（石油）provides around 40% of the world"s energy needs , mostly
fuelling automobiles.Coal is still used,mostly in power stations,to cover one一quarter of
our energy needs,but it is the least efficient,unhealthiest and most environmentally
damaging fossil fuel（矿物燃料）.Natural gas reserves could fill some of the gap from oil,
but reserves of that will not last into the 22nd century either. Most experts predict we will
exhaust easily accessible reserves within 50 years.Less-polluting renewable energy
sources offer a more practical long-term energy solution. "Renewable"refers to the fact t
hat these resources are not used faster than they can be replaced.
Hydroelectric（水力发电的）power is now the most common form of renewable energy,
supplying around 20%of world electricity.China"s Three Gorges Dam is the largest ever.
At five times the size of the US"s Hoover Dam , its 26 turbines（涡轮机）will generate the
equivalent energy of 18 coal-fired power stations.It will satisfy 3% of China"s entire electricity demand.
In 2003, the first commercial power station to use tidal（潮汐的）currents in the open
sea opened in Norway. It is designed like windmill（风车）,but others take the form of
turbines.
As prices fall,wind power has become the fastest growing type of electricity generation一
quadrupling（翻两番）worldwide between 1999 and 2005. Modern wind farms consist of
turbines that generate electricity.Though it will be more expensive,there is more than
enough wind to provide the world"s entire energy needs.Wind farms come in onshore and
offshore forms.They can often end up at spots of natural beauty,and are often unpopular
with residents.And turbines are not totally harmless一they can intertere with radar,alter
climate and kill sea birds.Scotland is building Europe"s largest wind farm,which will power
200,000 homes.The UK"s goal is to generate one-fifth of power from renewable sources,
mainly wind,by 2020.But this may cause problems,because wind is unreliable. Which country took the lead in making use of tidal currents to produce power in 2003?