People are beginning to use clean energy sources mainly because _______.
A: fossil fuels have caused a lot of pollution
B: clean energy is cheap
C: fossil fuels have cost a lot of lives
D: they do not have enough fossil fuels now
A: fossil fuels have caused a lot of pollution
B: clean energy is cheap
C: fossil fuels have cost a lot of lives
D: they do not have enough fossil fuels now
举一反三
- We have to prepare for a new age of energy synthesis since fossil fuels will be eventually depleted.
- Human beings have been depending heavily on fossil fuels to meet their increasing energy demands since the Industrial Revolution.
- 中国大学MOOC: We have to prepare for a new age of energy synthesis since fossil fuels will be eventually depleted.
- People are beginning to use clean energy sources mainly because _______.
- The burning of fossil fuels results in the pollution of the______.