23（）

A.The results of economic decisions cannot always be predicted.
B.Minimum wage cannot always protect employees.
C.Economic theory may predict the results of economic decisions if other factors not changing.
D.Economic decisions should not be based on economic theory.

A.some Kindle users got shocked in that they had no rights to download some books
B.the Internet search company put books online that are protected by copyright
C.the European Union shows concerns about copyrighted books
D.the sales of e-books at a lower price do harm to the profits of publishers and writers