NO.PZ2018062002000061
问题如下：
Devin, Egbert, and Humphrey, financial analysts from the same investment firm, gave the following personal insights on sector indices:
Devin:Sector indices track different economic sectors and cannot be aggregated to represent the equivalent of a broad market index.
Egbert:Sector indices provide a means to determine whether an active investment manager is more successful at stock selection or sector allocation.
Humphrey:Sector indices apply a universally agreed upon sector classification system to identify the constituent securities of specific economic sectors, such as consumer goods, energy, finance, health care.
Whose statement is most correct?
选项：
A.
Devin.
B.
Egbert.
C.
Humphrey.
解释：
B is correct.
The Sector Index provides a way to determine whether an active investment manager is more successful at stock selection or sector allocation.
考点：行业指数
这道题就是考察行业指数的用途：
Devin:行业指数跟踪不同的经济部门，不能汇总到一起代表一个广泛的市场指数。（后半句说反了，can be aggregated to represent the equivalent of a broad market index）
Egbert:行业指数提供了一种方法来判断一个活跃的投资经理在股票选择或行业配置方面是否更成功。正确
Humphrey:行业指数应用一个公认的行业分类系统来识别特定经济部门的组成证券，比如消费品、能源、金融和医疗。(错，不存在universally agreed upon sector classification system)
a选项为什么错呢？所以a选项到底能不能汇总代表？can还是cannot
