Match the four basic kinds of workplace labor agreements with the correct description. Closed shop Closed shop drop zone empty. Union shop Union shop drop zone empty. Agency shop Agency shop drop zone empty. Open shop Open shop drop zone empty. Employers may hire only workers who are already in the union. Workers may choose to join or not join a union. Workers must join the union within a specific time after being hired. Workers must pay equivalent of union dues, but are not required to join the union