On the top of Mount Everest, the total atmospheric pressure is reduced to 33.73 kPa (about one-third of its value at sea level).
Assume that the fraction of the atmosphere that is made up of oxygen is the same at all elevations.
If the partial pressure of oxygen at sea level is 21 kPa, what is the partial pressure of oxygen on the top of Mount Everest?
A 12.73 kpa
B 11.2 kpa
C 54.73 kpa
D 7.0 kpa

Sorry i dont understand the question can you rephase it?

Answerd. may include all of these are many definitions of bases: the  brønsted-lowry definition of acids and bases says that bases are proton acceptors.the arrhenius definition of acids and bases says that bases increase [oh⁻] in solution (thereby producing oh⁻ ions)the lewis definition of acids and bases says that bases donate electron pairs.therefore, the sensible answer is that a base may include all of the described characteristics.