第1个回答 2019-04-30
A man wants to bring down the bricks from upstairs.He pulled a box upstairs with a fixed pulley, climbed a ladder and put the bricks in the box, but when he put the bricks on the ground, he accidentally lifted himself up through the pulley.The box became lighter because the bricks fell on the ground. He was wheeled to the ground. Unfortunately, he was hurt by the bricks on the ground.本回答被网友采纳