A __________ is a mechanism that attaches to a vertical pole and can be pumped up and down the pole. It is used to support the planks on which workers stand.
A) fabricated frame scaffold
B) portable ladder
C) modular frame scaffold
D) pump jack

Question

Quizplus · Accepted Answer

The description of the mechanism matches that of a pump jack, which is designed to be attached to a vertical pole and pumped up and down to support workers' planks. The other choices either do not fit the description or are not specifically designed for this purpose.

A __________ Is a Mechanism That Attaches to a Vertical