某机字长32位,采用定点小数表示,符号位为1位,有效值为31位,则可表示的最小负小数为( )。
A. +(231-1)
B. -(1-2-32)
C. +(1-2-31) ≈+1
D. -(1-2-31) ≈-1
Which of the following is NOT one of the four main categories of online marketing communications?
A. Web sites
B. guerrilla marketing
C. display ads
D. e-mail
Which of the following is an advantage of online communications for marketers?
A. Consumers cannot effectively screen out your messages.
B. Companies can accurately track how effective their ads are because software filters out all bogus hits.
Companies can offer tailored information or messages that engage consumers.
D. Advertisers do not need to worry as much about context.
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