A woman joins a package shipping firm as a truck driver. She is required to join the labor union six weeks after she starts work, and she must remain a member. A/An ____ shop is the type of union arrangement that exists at the firm. A woman joins a package shipping firm as a truck driver. She is required to join the labor union six weeks after she starts work, and she must remain a member. A/An ____ shop is the type of union arrangement that exists at the firm. agency closed modified union union