Will solar and wind replace fossil fuels within 20 years?

1. Will solar and wind replace fossil fuels within 20 years?
Will fossil fuels…………………………………..
2. This is the second time I have visited Yaly hydroelectric power plant.
I have……………………………………….
3. They built the first hydroelectric power plant in Niagara Falls in 1879.
The first hydroelectric power plant……………………………
4. Although coal is the most polluting of fossil fuels, it is still the largest sources of energy worldwide.
Despite……………………………..