'.BAK' extension refers usually to what kind of file?
A). Backup file
B). Audio file
C). Animation/movie file
D). MS Encarta document
1. 'CD' computer abbreviation usually means ?
2. In which decade was the ARRL founded?
6. The material known in commerce as Terylene is a
7. Terylene is a condensation polymer of ethylene glycol and which acid?
8. Choose the word which is different from the rest.