fuels formed millions of years from the remains of animals and plants

nuclear energy

solar power

fuel formed from the energy of the wind

are

be

being

to be

He hasn't visited London for three years.

He was in London for three years.

He didn't visit London three years ago.

He has been in London for three years.

talent

talented

distinguish

respectful

respected

because

a

man

An/ the

the/ an

an/ an

the/ the

Because of

attacks

suggested

to stop

Human using sunlight to stay warm

The need to develop new technology for solar power system

How the energy of sunlight is used

How solar energy can provide power for transportation systems

It is her best piece of nonfiction

It is an autobiography

It is a typical novel of the 1960's.

It is a fictional work based on another person's experiences.

durable

long-lasting

steady

temporary