Questions

1.Logout of your computer each time you have finished using it

2.Install and use anti-virus software on your computer 

3.Do not use emails on your machine

4.Make sure all your files are safely stored to your floppy disks

Biodegradable substances can be broken down into simpler, harmless substances in nature with due course of time by the biological process such as action of microbes. They can be recycled as a part of food chain.

Here, Leather bags are biodegradable.

The part of the earth and its atmosphere in which living organisms exist or that is capable of supporting life is called Biosphere.