No clue to be honest with ya buddy
Answer:variable interval
Explanation:
In operant conditioning, a variable-interval schedule is defined as that schedule in which a response is received after unpredicted time , because reinforcement has been administered in diffrent non fixed times. The response is slow and steady. Variable means non fixed time which means reinforcement can occur at any time , using various different time zone. Interval refers to time hence this means reinforcement is administered at various times.
Answer: toeboard
Explanation: The Occupational Safety and Health Administration defines the Walking-Working surfaces regulation for the secure construction of stairs in industrial environments. For platforms or walls that are 4 feet or higher above the ground and do not have surrounding walls, it is mandatory to build a standard railing around them. In cases where there is a moving machinery, people can pass or there is an equipment which would be harmful when falling objects come in contact with it, the railings must have a toeboard.
A toeboard is an equipment fixed vertically to prevent items from falling for the platform.
This is from Thomas Paine's book Common Sense that was published in January of 1776.