Viết ít nhất 150 từ trong khoảng 20 phút.
The pie charts show the main sources of energy in the USA in 1980 and 1990. The sources are oil, natural gas, coal, hydroelectric power and nuclear power.
Overall, oil was the most important source of energy in both years, but its share decreased. Coal and nuclear power increased, while hydroelectric power did not change.
In 1980, oil provided 42% of the energy in the USA, which was the biggest share. Natural gas was second with 26%, and coal was third with 22%. Hydroelectric power and nuclear power were very small, at only 5% each.
In 1990, the share of oil fell to 33%, but it was still the largest source. Natural gas decreased slightly to 25%. On the other hand, coal increased from 22% to 27%, so it became the second biggest source, higher than natural gas. Nuclear power also doubled from 5% to 10%. Hydroelectric power stayed the same at 5% in both years. This shows that the USA used less oil and more coal and nuclear energy in 1990.