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"It's unfair that people keep saying the Chinese are too young to compete,"

Half of the team - He Kexin, Yang Yilin, Jiang Yuyuan - is under age if online sports registration lists in China are correct. The international gymnastics federation, however, said those gymnasts were eligible and that the ages on their passports were correct.

China's floor routines were not perfect, but they were good enough to win.

The aftermath of the competition can also be emotionally difficult, and neither team faced easy questions after the competition.

“30 billion illegal downloads in 2007“

“Even the most innovative business models are totally undermined by free music”

gets so hot that it can boil water into steam

team can then be used to turn a turbine to make electricity.

California's Mojave desert, there are huge rows of solar mirrors arranged in what's called "solar thermal power plants"

this idea to make electricity for more than 350,000 homes

problem with solar energy is that it works only when the sun is shining

cloudy days and at night, the power plants can't create energy.

solar plants, are a "hybrid" technology

daytime they use the sun

night and on cloudy days they burn natural gas to boil the water so they can continue to make electricity.

form of solar power plants to make electricity is called a Central Tower Power Plant, like the one to the right - the Solar Two Project.

Sunlight is reflected off 1,800 mirrors circling the tall tower

mirrors are called heliostats

move and turn to face the sun all day long

light is reflected back to the top of the tower in the center of the circle where a fluid is turned very hot by the sun's rays.

luid can be used to boil water

make steam to turn a turbine and a generator.

We can also change the sunlight directly to electricity using solar cells.

Solar cells are also called photovoltaic cells

PV cells for short

be found on many small appliances

calculators

even on spacecraft

first developed in the 1950s for use on U.S. space satellites

made of silicon, a special type of melted sand.

sunlight strikes the solar cell, electrons (red circles) are knocked loose

move toward the treated front surface (dark blue color)

electron imbalance is created between the front and back

two surfaces are joined by a connector, like a wire, a current of electricity occurs between the negative and positive sides.

individual solar cells are arranged together in a PV module and the modules are grouped together in an array.

arrays are set on special tracking devices to follow sunlight all day long.

electrical energy from solar cells can then be used directly

used in a home for lights and appliances

in a business

Solar energy can be stored in batteries to light a roadside billboard at night

energy can be stored in a battery for an emergency roadside cellular telephone when no telephone wires are around.

17-year-olds typically strained or sprained their lower limbs

. But in terms of catastrophic injuries like neck breaks, it ranks right up there with ice hockey