单项选择题
单项选择题 Phosphorus is used in paints for highway signs and marks because it is bright at night.
单项选择题 Furthermore, the campaign itself was lavishly financed, with plenty of money for top flight staff, travel, and television commercials.
单项选择题 They make better use of the time they have, and they are less likely to succumb to fatigue in stressful jobs.