多谢RENEE的解答。另外关于那个车速耗油题目,我查了一下,MPG is a measure of fuel economy (or 'gas mileage'), For example, 20% better mileage does not mean 20%, but 16.7% less fuel. This comes from the following calculation: 20% is 1.2 times bigger distance, therefore 100% / 1.2 = 83.3% of the original fuel consumption, or 16.7% less fuel. (http://en.wikipedia.org/wiki/Miles_per_gallon) 如果是这样理解的话,那么40miles per hour 要比80 miles per hour 省一半的油,如此一来,此题的答案是不是应该选2呢?多谢指正! 见下面---- 40mile/h的速度行驶了40,80mile/h的速度行驶了80。40miles per hour耗油1gallon,如果gallon mileage相等时,80mile per hour应该耗油2gallon。因为题干说40better than 80,所以我觉得80mile per hour油耗应该大于2 gallon,所以应该是2*1.5=3,而不是2/1.5=4/3 |