How does a vaccine work?
a. it kills viruses.
b. it protects cells from viral infection.
c. it prepares the immune system to recognize viruses.
d. it prevents viruses from being transmitted from an infected person.

The idea that all living things are made up of cells is considered scientific law. this means the idea is an emerging scientific idea that has a logical explanation. has been tested with similar results at least twice. is supported by scientific consensus and a large amount of evidence. has been rejected only once by the scientific community

Is becoming less expensive to screen blood samples for dna certain diseases have genetic basis what is possible ethical concern about the availability of inexpensive dna testing

What process decreases the salinity of ocean water? decreased precipitationdecreased melting of glaciersincreased evaporationincreased runoff from rivers