Vaccines and shots are typically made of a small controlled portion of the virus or disease to cause immunity to the large scale types.
Answer:
Explanation:
I am not that sure but according to me it will be the option 3.
Answer:
Carbon dioxide, nitrous oxide, and methane
Explanation:
Veins contain valves that ensure blood flows in only one direction. Valves also help blood travel back to the heart against the force of gravity.
Hope this helps.....
