An object is moved closer to a lens. Does the focal length of the lens increase, decrease, or stay the same?

Stay the same

Explanation:

The focal length of a lens is determined by its radius and by the indexes of refraction.  The distance of the object does not affect the focal length.

as a general rule, scissors have blades less than 6 in (15 cm) long and usually have handles with finger holes of the same size. shears have blades scissors used to cut hair or fabric must be much sharper

it doesn't. it was imagined up in the middle ages.