What does relative humidity measure?

the amount of water in cirrus clouds
the amount of water that has evaporated into the air
the amount of frozen water that has condensed from the air
the amount of water vapor in the air compared to the amount the air can hold

The spermists believed that: the male made the only hereditary contribution to the offspring the male and female traits were blended in the offspring the female made the only hereditary contribution to the offspring the male and the female made equal contributions to the next generation