Complete the passage using suitable connectors:

Computer virus is a terror to the users of computer. (a) _____ it is not biological virus, it disturbs the plain operation of a computer. Computer virus is usually a programme to delete the files which are saved (b) _____ useful memories. Sometimes the virus attacks the hard disk (c) _____ harms it. (d) _____ things happen (e) _____ no operation is possible after the attack.

Complete the passage using suitable connectors.

Dengue fever is a serious disease (a) ____ is caused by a sort of virus called 'Dengue virus'. (b) ____ , this virus was identified in Africa. (c) ____ now it has spread all over the world. (d) ____ in most cases, dengue has its remedy, it is better to prevent it. (e) ____ we keep our dwelling places clean and people are aware of it, we can easily prevent this disease.