Answer:
c. is the only answer that doesn't say you are using drugs.
Answer:
antigens
Explanation:
a vaccine may contain that
Answer:
Plants can't use N2 as is so the first option is wrong. They do have relationships with bacteria that live in nodules of the root and convert the nitrogen into ammonia, a usable form for the plants. So the second option is correct. There are bacteria living in the soil as well that convert nitrogen to ammonia so technically option 3 is also correct. Again, nitrogen if present in water would be in the form N2 which is not usable by plants so 4 is wrong.
These are correct:
use bacteria to convert nitrogen to usable form
In obtain usable nitrogen compounds from the soil
