What natural disaster buried an entire town in ash?
a. the volcanic eruptions of mt. vesuvius
b. the galveston hurricane
c. the san francisco earthquake
d. the japanese tsunami

the dark variety, as they are not visible on the dark tree barks

explanation:

the relative standard reduction potential of the half-cell in which reduction occurs; more positive than the other half-cell. reduction is a chemical process in which electrons are added to an atom or an ion; it always occurs accompanied by oxidation of the reducing agent.