2 percent of Chinese families buy prescription medicines and store them at home for later use. Of them, about 80 percent throw away medicines that have passed their use by date, a survey reveals.Officials said the government should introduce laws to regulate the collection and disposal of out-of-date medicines. A risk analysis system for medicines should also be established, the experts said. To study the way people stored medicines and the way medicines were handled after they had passed their used by date, the survey covered more than 1,800 families in 18 cities and counties from Shanghai, Beijing, Guangdong, Shandong, Sichuan and Inner Mongolian Autonomous Region between October and November in 2007. In Shanghai, 56.4 percent of the residents said they threw away out-of-date medicines and 25.5 percent returned them to pharmacies, the highest percentage recorded of all the regions in the survey.About 60 percent of residents knew that out-of-date medicines could be an environmental threat and 75.3 percent were aware of the dangers involved in selling out-of-date medicines to illegal drug dealers. "The dangers in using out-of-date medicine are more serious than the adverse reactions to drugs. Local drug authorities have begun education campaigns to teach residents to return out-of-date medicines," said the vice director of the Shanghai Clinical Center for Drug Adverse Reaction Monitoring."There were some 15,000 adverse drug reaction cases in the city last year. About 90 percent of these were caused by improper use of drugs, and one of the main causes of this was people using out-of-date medicines." 21. How many Chinese families throw away medicines that are out of date? A) 56.2 percent. B) 80 percent. C) More than 80 percent. D) Less than 50 percent. 22. The government is expected to . A) dispose of out-of-date medicines carefully B) introduce laws and set up a risk analysis system C) educate people not to take out-of-date medicines D) inform people of the danger of out-of-date medicines 23. The purpose of the survey is to . A) study how people stored and handled medicines B) cover as many families and countries as possible C) provide some information for the government D) study the medicines in a proper way 24. Which of the following is TRUE according to the survey? A) Most provinces in China are included in the survey. B) Many people sold out-of-date medicines to illegal drug dealers. C) People in Shanghai did best in handling out-of-date medicines. D) Few people knew out-of-date medicines would harm the environment. 25. Those people who took out-of-date medicines might . A) be asked to return the medicines B) be accused of by the drug authorities C) be required to attend educational classes D) suffer from adverse drug reactions