单选题 It may be summertime, but the living isn't easy-not for weary workers whose last vacation is a distant memory. According to one recent study, 1 in 4 employees in the United States doesn't get any paid vacation. Almost half don't take even a week off every year. Economists estimate that the average American works one more month per year today than in 1976. Small-business owners are taking this daily grind to a whole new level. The number of employers at companies with fewer than 100 workers who plan to take a summer vacation has continued to fall in the past four years. Two in three bosses worry about their businesses when they're out of the office. Fully 75 percent check in by phone or E-mail even when they're on "vacation," many of them several times a day. But is all this work good for business? As the last weeks of summer vacation days slip away-yet again, researchers are insisting these extreme jobs have a dark side. All work and no play really can make Jack a dull boy: Apart from health risks that come with overwork, people who don't get out of the office tend to be less creative, less productive, and, ultimately, less effective. If there is one thing small-business owners can do to improve their companies' performance, experts say, it is take some time off. There's a good chance the benefits of vacation will go straight to the bottom line. According to a study by American Express, more than a third of small-business people say their best ideas-the ones that lead to business growth-come not at work but during their downtime. "Having a life outside of work doesn't detract from work success" but enhances it, a study by the Families and Work Institute concluded in 2005. Happier people, no surprise, tend to be more productive than unhappy people. Two business professors, Sigal Barsade of the University of Pennsylvania's Wharton School and Donald Gibson of Fairfield University, found in a recent study that employee moods have a measurable effect on just about everything anyone does at work-job performance, decision making, creativity, turnover, teamwork, and leadership. Overwork also comes with serious health risks. Researchers have found that people who work long hours can even become addicted to their own stress hormones. They feel sluggish when they're out of the office, so they head back for their fix, and the cycle repeats itself. Continuous stress also affects the performance of the part of the brain responsible for memory.

单选题If injured, the fireman will ______.

单选题Women have occupied the high moral ground for so long because