问题
单项选择题
The sentence "our life span outpaces our usefulness" means we can live longer ______.
A．and make progress
B．and do more work
C．but move slowly
D．but become useless
答案
参考答案：D
解析：[分析] 细节题型。 根据第三段的最后一句It appears that our life p is outpacing our usefulness in society．outpace“超过”。