As a speaker, if your purpose is to emphasize a specific point you have visually depicted on the slideshow, how could you use body language to meet that purpose? A. Gesture with your arms and hands in the air to emphasize points.
B. Point directly to the screen to draw listeners’ attention.
C. Open your chest and keep you back straight.
D. Use the physical space. Walk around the room.

answer: b (host)

viruses use the cells of living organisms to reproduce. the cell which is used by virus is called as "host cell". it is a living cell in which virus multiplies, example bacteria, plant or an animal cell.

in this, the virus is a parasite, which uses host cell for its benefit (reproduction) by using the cell machinary of host cell.

a is the indefinite article

hasty generalization

easy - boys have problems.

i hope this ! (: