A、To appeal for higher wages. B、To demand better health care. C、To call for a permanent security guard. D、To dismiss the bad-tem

Staff at a suburban supermarket in Melbourne say they feel unsafe at work after security guards were removed. This came after a series of physical attacks and verbal abuse by customers. More than 50 workers at the store have signed a letter calling for a permanent security guard following a series of incidents, including a customer threatening to attack a supervisor with a knife. A security worker had guarded the store each night from 7 p.m. until 12 a. m., but that had stopped suddenly on Monday, employees said. One worker said an angry customer had thrown a chicken at his head after complaining about how long she had waited to be served. Another worker said the lack of protection at the store made her feel uncomfortable at work. However, the spokesman of the supermarket said the store had taken strong action in response to incidents. "We have found very few instances of bad customer behavior at our store in the past year. In the rare cases we have seen bad behavior, we have taken strong action in response, including banning a customer from the store."
3.   For what purpose did the staff at a supermarket in Melbourne sign a letter?
4.   What did the spokesman of the supermarket say regarding the employees’ demand?