共用题干 第一篇Renewable Energy SourcesToday petroleum provides around 40%of the world's energy needs,mostly fuelling automobiles.Coal is still used,mostly in power stations,to cover one-quarter of our energy needs,but it is the least efficient,un- healthiest an

共用题干
第一篇

Renewable Energy Sources

Today petroleum provides around 40%of the world's energy needs,mostly fuelling automobiles.Coal is
still used,mostly in power stations,to cover one-quarter of our energy needs,but it is the least efficient,un-
healthiest and most environmentally damaging fossil fuel.Natural gas reserves could plug 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.We could fast reach an energy crisis.We need to rapidly develop
sustainable solutions to fuel our future.Less-polluting renewable energy sources offer a more practical
long-term energy solution. They may benefit the world's poor too."Renewable"refers to the fact that these
resources are not used faster than they can be replaced.
The Chinese and Romans used waterinills over 2, 000 years ago.But the first hydroelectric dam was built
in England in 1870.Hydroelectric power is now the most common form of renewable energy,supplying around
20%of world electricity.China's Three Gorges Dam,which has just been completed,is the largest ever. At
five times the size of the US's Hoover Dam,its 26 turbines will generate the equivalent energy of 18 coal-
fired power stations.It will satisfy 3%of China's entire electricity demand.Surprisingly,some argue that hy-
droelectric dams significantly contribute greenhouse gases.
In 2003,the first commercial power station to harness tidal currents in the open sea opened in Norway.
It is designed like windmill,but others take the form of turbines.
As prices fall,wind power has become the fastest growing type of electricity generation一quadrupling
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 un-
popular with residents.And turbines are not totally benign一they can interfere with radar and leave a signifi-
cant ecological footprint,altering climate and killing sea birds.Migrating birds may have more luck avoiding
them.Scotland is building Europe's largest wind farms,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 is the country with the first commercial power station that makes use of ocean currents produced by tides?
A:China.
B:Norway.
C:England.
D:America.