HELP ASAP PLSSS Which type of current typically carries cold, dense water from the poles toward the Equator?

Regarding most of the narrator’s story, which word best describes the tone?

Some tools have graduations to show multiple measurements. for example, a ruler may have graduations for both millimeters and centimeters. when measuring the length of an earthworm, which graduations would allow for the most accurate measurement? millimeters centimeters decimeters meters

What is the difference between a scientific hypotheses and a scientific theory?