Which organisms feed on host organisms, causing them harm?

Petter is a middle aged overweight man who is trying to decrease his body circumstance . how could the serving size on a neutrino label him lose weight ?

Does pretroleum jelly your hair grow

What is one way that cold and flu viruses spread? a.by transfusing contaminated blood b.by inhaling contaminated droplets c.by eating contaminated meat d.by drinking contaminated water