What single issue party worked to stop the spread of slavery?

The Free Soil Party.

Explanation:

Their slogan was "Free men on free soil constituted a moral and economically superior system to slavery". They also worked against laws that discriminated the freed african americans in other states. The party was born in NY after the Wilmot Proviso was derogued, that law would have banned slavery.

hygrometers and hair thermometers (often found as part of hygrometers/psychrometers) can be used to measure humidity. barometers are used to measure atmospheric pressure, while anemometers are used to measure wind speed. so the 2nd and 4th choices should be the correct answers.

productive most commonly means: achieving or producing a significant amount or result.

explanation:

productive can also mean:

these depend on how the word productive is used. most likely productive will mean   achieving or producing a significant amount or result.