Why were the slaves not able to escape slavery back then?

a lot of them didn't know they could

Explanation:

If they tried to run and get caught they got hurt by their master and they sorta had no way before Harriet Tubman.

Explanation:

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.

answer; clear and present danger test;