Read the definitions carefully and select the correct words.
1. produced and used to protect the main memory of a computer against infection by a virus
2. to make a copy of information stored on a computer
3. a copy of a computer document, program etc, which is made in case the original becomes lost or damaged
4. a plastic or rubber tube containing wires that carry telephone messages, electronic signals, television pictures etc
5. one of several parts that together make up a whole machine, system etc
6. slightly wet, often in an unpleasant way
7. towards a lower level or position
8. relating to the outside of something
9. to stop functioning properly, usually temporarily
10. inside something rather than outside
11. to connect a piece of electrical equipment to the main supply of electricity, or to another piece of electrical equipment
12. if you reboot a computer, or if it reboots, you start it up again
13. to damage something so badly that it loses all its value, pleasure, etc
14. to disconnect a piece of electrical equipment by pulling its plug out of a socket
15. to add the most recent information to something
16. moving or pointing towards a higher position
17. to rub a surface with something in order to remove dirt, liquid etc