1. Describe 2 methods of viral infection

Question

2. How can a virus be helpful to its host?

Please this is very urgent, I have finished everything else but these r my last 2 questions that I don't know! Please help! Thanks:)

Answer 1

http://www.webmd.com/a-to-z-guides/bacterial-and-viral-infections

http://microbemagic.ucc.ie/about_microbes/good_viruses.html