今天我们要学的词是 rule of thumb. Rule of thumb 经过反复实践，得出的一般规律。一项最新研究指出，少吃能长寿。The rule of thumb is that by eating 15 percent less starting at age 25 you could add 4.5 years to your life. 一般规律是，如果你从25岁开始，饭量减少百分之15，就能多活四年半。如今油价飞涨，省油的高招之一是：As a rule of thumb, shut off your engine if you expect to be sitting for more than 30 seconds. 一般来说，如果停车超过半分钟，就应该熄灭引擎。好，今天我们学习的词是 rule of thumb, rule of thumb, rule of thumb.
