问题
单项选择题
What does unwanted e-mail messages do to the providers of the Internet services
A．Raising their cost.
B．Raising the Internet speed.
C．Improving their business.
D．Attracting investment.
答案
参考答案：A
解析：[分析] 细节题型。 见第四段第一句：The growth in unsolicited commercial electronic mail imposes significant monetary costs on providers of Internet access services，businesses，and educational and nonprofit institutions that…因此选项A是答案。