Some British supermarket companies are asking their warehouse workers to wear small computers, calling 'electronic tags'. The 【M1】______ companies say that these tags will to help them to reduce costs 【M2】______ and increase the efficient delivery of goods and food to stores. The system uses American satellite and radio technology send messages to the workers. In a report Professor Blakemore 【M3】______ from the University of Durham said that the use of these tags is making some workplaces more like prisons. 【M4】______ The technology arrived from the US at the start of the year and more and more companies are using it. Almost 10,000 employees are using it to supply good to well-known British 【M5】______ supermarkets. Trade unionists representing workers are worried that companies could use the technology to check what workers are doing work. They are asking for special 【M6】______ measures to make sure that this does not happen. Under the system, workers have to wore computers on 【M7】______ their wrists, arms and fingers, and sometimes they have to wear a special vest contained a computer that instructs them 【M8】______ where go to collect goods from warehouse shelves. 【M9】______ The system also allowed the store to send orders to workers' computers. 【M10】______ 【M1】