Roundworms may be free-living or parasitic, and parasites are organisms that live off a host. Given these facts, aside from free-living, where else can roundworms exist among the following options:
- mouth of rivers
 - in the sky
 - loose soil
 - our planet
 - Earth orbiting the Sun
 - live off a host
 - molecules
 - h2o


 

      live off a host   