- A rainforest is a kind of forest
- Cutting down trees in a forest causes the number of trees to decrease in that forest
- Hence, cutting down trees in a rainforest causes the number of trees to decrease in that rainforest

- Cutting down trees in a rainforest causes the number of trees to decrease in that rainforest
- A decrease of something is a kind of change
- So, cutting down trees in a  rainforest changes that rainforest

- A forest is a kind of environment
- A rainforest is a kind of forest
- So, a rain forest is a kind of environment

- Cutting down trees in a  rainforest changes that rainforest
- A rain forest is a kind of environment
- Humans changing an environment sometimes causes that environment to be destroyed
- So, humans cutting down trees in a rainforest can cause that rainforest to be destroyed

- Humans cutting down trees in a rainforest can cause that rainforest to be destroyed
- Destroying something causes harm to that something
- Therefore, humans cutting down trees in a rainforest causes harm to that rainforest

- Humans cutting down trees in a rainforest causes harm to that rainforest
- Harming an environment causes harm to the living things / to the organisms in that environment
- Therefore, humans cutting down trees in a rainforest causes harm to the organisms in that rainforest

- Rainforests contain many species
- Species means a group of a certain kind of organism
- Hence, rainforests contain many kinds of organisms

- Humans cutting down trees in a rainforest causes harm to the organisms in that rainforest
- Rainforests contain many kinds of organisms
- So, humans cutting down trees in a rainforest causes harm to many kinds of organisms

- Humans cutting down trees in a rainforest causes harm to many kinds of organisms
- Organisms are a part of an environment
- Therefore, humans cutting down trees in a rainforest causes harm to much of the environment

- Humans cutting down trees in a rainforest causes harm to much of the environment
- To cut down a rainforest means to cut down trees in a rainforest
- Hence, humans cutting down a rainforest causes harm to much of the environment

Hence, humans cutting down a rainforest causes harm to much of the environment
[Question]Which human activity is most harmful to the natural environment?
[Context]- Rainforests contain many species 
- A decrease of something is a kind of change 
- Organisms are a part of an environment 
- Harming an environment causes harm to the living things / to the organisms in that environment 
- A rainforest is a kind of forest 
- Cutting down trees in a forest causes the number of trees to decrease in that forest 
- To cut down a rainforest means to cut down trees in a rainforest 
- Humans changing an environment sometimes causes that environment to be destroyed 
- Species means a group of a certain kind of organism 
- A forest is a kind of environment 
- Destroying something causes harm to that something