试题题干
Translate the following sentence into Chinese.
In the United States, for instance, the mortality rate for lung cancer among female non-smokers has not changed during the past 20 years. During the same period, the rate among female smokers has increased by a factor of half.
参考答案
试题解析
考点：for instance 例如；the mortality rate 死亡率；increase by a factor of half 增加了一半。
句子结构：第一句中主语为the mortality rate for lung cancer among female non-smokers。第二句During the same period为时间状语。