单项选择题
A. an attempt to bring down a website or other online service.
B. a prank where someone sends an unauthorized e-mail attempting to close a user’s e-mail account.
C. stealing a user’s identity and making changes to their accounts.
D. an attempt to change a user’s password to prevent access to a service by repeatedly guessing the user’s information.
单项选择题 A dry cleaner is having issues with their computer overheating. Which of the following preventive maintenance techniques would be the BEST short-term resolution to the problem?（）
单项选择题 Which of the following connectors is MOST commonly used for UTP cable?（）
单项选择题 An end user reports that their computer is not performing as fast as it used to and it shuts down unexpectedly. Which of the following is the MOST likely cause?（）