Not sure, what youre talking about
Oral polio vaccine is highly effective and inexpensive (about US$0.10 per dose, or US$0.30 per child and its availability has bolstered efforts to eradicate polio. A study carried out in an isolated Eskimo village showed that antibodies produced from subclinical wild virus infection persisted for at least 40 years. Because the immune response to oral polio vaccine is very similar to natural polio infection, it is expected that oral polio vaccination provides similar lifelong immunity to the virus.
Contact immunity to polio can occur when attenuated poliovirus derived from the oral polio vaccine is excreted, and infects and indirectly vaccinates unvaccinated individuals.
Answer:
A
Explanation:
if you hide a storm drain it really doesn't do much because it doesn't clean the water, and all of the other options do clean water of contaminants.
DNA is going to be the answer
The three changes of state during which energy is absorbed are:
1. Change from solid to liquid - Melting.
2. Change from liquid to gas - Vaporization
3. Change from solid to gas - Sublimation
All these changes of state require heat energy to break the attractive forces that hold the particles of the molecules together, so that they can move into more disorderly states. For instance, when heat is applied to a solid, the solid absorbs the heat and use it to break the attractive forces that are holding the molecules of the solid together. At a particular temperature, the attractive forces will be completely overcome and the solid framework will collapse, thus leading to the melting of the solid.
