题目

Read the following passage. Summarize the main idea and themain point(s) of the passage in no more than 60 words. Use your own words asfar as possible.Whatcomes first: the optimism or the good health? Optimism, defined as the generalexpectation that the future will be favorable, could provide ways to improvehealth, some researchers believe. But scientists remain unsure if optimism goesahead of health improvements, or vice versa. A recent study suggests that most peoplecan't help but to think optimistically. This study was conducted by Ed O'Brien,a social psychologist at the University of Michi下列做法不符合安全用电要求的是（ ）A．电灯开关必须接在零线上B．家用电器的金属外壳一定要接地C．家用电器失火时，必须先切断电源，然后再救火D．不要用湿布擦抹电器