改错题 This paragraph contains 15 errors, either in grammar, writing mechanics, punctuation or in coherence. Pick out the errors and correct them. One of the recent developments in modem technology, cellular phones, can be a threat to safety. A study for Donald Redmond and Robert Lim of the university of Toronto showed that cellular phones poses a risk to drivers. In fact people who talk by the phone while driving are four times more likely to have an automobile accident than those whom do not use the phone while drive. I like to use my cell phone when I am driving because it is convenient. The researchers studied 699 drivers. Who were in an automobile accident while they were using their cellular phones. The researchers concluded that the main reason for the accidents was not that people used one hand for the telephone and one hand for driving. Instead the cause of accidents were usually that the drivers became distracted angry or upset by the phone call. As a result, the drivers' lost concentration. Many people find that monthly plans are more economical than pre-paid plans.