问题
According to the text, what is the major cause of the flooding spam？
A:Companies rely on e-mails for communications.
B:More people in the world communicate by e-mails.
C:Many computer viruses contain spam e-mails.
D:More advertisers begin to promote sales through spam.
B:More people in the world communicate by e-mails.
C:Many computer viruses contain spam e-mails.
D:More advertisers begin to promote sales through spam.
正确答案是：
