CBSE Class 9 Biology Natural Resources
- why doesn,t the level of oxygen in the atmosphere decrease
- 1) How is greenhouse effect and global warming related? Explain 2) Give any three human activities that would that are responsible for depletion of Ozone Layer.
- who discovered nuclear weapons
- What is natural resources?
- Who is more poisonous among sulphur dioxide and carbon monoxide?
- What is natural resources
- What is natural resources
- when does this fog disappear
- What is Science?
- What are the 3 cause of greenhouse effect