May Day or International Workers' Day is observed on May 1 all over the world today to commemorate the historical struggle and sacrifices of the working people to establish an eight-hour workday. It is a public holiday in almost all the countries of the world.
Since the Industrial Revolution in the 18th and 19th centuries in Europe and the US, the workers in mills and factories had been working a long shift, fourteen or even more hours a day.
On May 1st in 1886, inspired by the trade unions, half of the workers at the McCormick Harvesting Machine Company in Chicago went on strike demanding an eight-hour workday.) Two days later, a workers' rally was held near the McCormick Harvester Machine Company and about 6000 workers joined it. The rally was addressed by the labour leaders. They urged the workers to stand together, to go on with their struggle and not to give in to their bosses. At one point of the rally, some strike breakers started leaving the meeting place. The strikers went down the street to bring them back. Suddenly, about 200 policemen attacked them with clubs and revolvers. One striker was killed instantly, five or six others were seriously wounded and many others were injured. The events of May 1, 1886 are a reminder that workers will continue to be exploited until they stand up and speak out to gain better working conditions, better pay and better lives.
Choose the correct answer form the following alternatives :
The word 'commemorate' used in the passage means ___