四六级考试

【单选题】 Grinols is primarily concerned with _________in his new book.
A．demonstrating the prevalence of gambling
B．examining the benefits and costs of gambling
C．exploring the causes of gambling
D．showing whether the benefits of gambling outweigh its costs

网考网参考答案：D
网考网解析：
本题为细节理解题。据第5段可确定。 查看试题解析出处>>