Which one of the following has been difficult to enforce due to the fact that over 50 percent of all spam originates from servers outside the United States? A: Spam blocking B: E-mail filtering C: Photo identity D: CAN-SPAM Act

美国CAN-SPAM法案：

What is spam? Spam is _____ email.

Which description about text classification in SMS spam control is wrong? A: Text classification relies on the patterns of SMS spam B: Machine learning is widely used in text classification C: Text classification uses phone numbers to filter SMS spam D: Text classification can be applied at a mobile cellular operator

‏执行以下代码的结果是：‏spam = 'hello' spam + 'world' print(spam)‏‏

有以下代码L = ('spam', 'Spam', 'SPAM!')下面那项是不正确的 A: L[2] 'SPAM!' 读取第三个元素 B: L[-2] 'Spam' 反向读取,读取倒数第二个元素 C: L[1:] ('Spam', 'SPAM!') 截取后2个元素 D: L[0:1] ('Spam', ') 截取中间的第2个元素

A more effective approach to controlling spam ha been the development and use of spam blockers, also known as ________. A: spam B: spam filters C: antivirus D: e-mail system

spam

spam='he ll o world 'he='or'he in spam 输出True

以下程序执行后的结果是：spam=40 spam=spam+2 print(spam) A: 42 B: 40 C: error D: 2