Task：The diagrams below show the amount of energy lost in 100 units when it is generated from black coal and when it is generated from brown coal.
Sample answer：
The diagrams present how 100 units of energy lost when it is produced from black coal and brown coal.
It can be seen from the first diagram that in the beginning black coal that can generate 100 units of energy is transported to the power station where electricity is produced. During the process, 68 units is lost so only 32 units of energy remains. Before consumers get the energy from black coal, the loss of another 3 units occurs as it is distributed and transmitted.
Referring to brown coal, when it is used in the electricity generation, more units was lost (73 units) while the amount of energy lose in the stage of distribution and transmission is the same as that in black coal. Finally, the remaining 24 units of energy is gained by people.
In conclusion, it is noticeable that less energy can be available for consumers if brown coal is applied to generate electricity.
(156 words)