单项选择题

A Denial of Service (DoS) attack is:（）

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.

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热门试题

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?（）

A. Update the firmware on the machine to accommodate for higher temperatures.
B. Use Disk Cleanup and Defrag to keep the machine from working as hard.
C. Use a can of compressed air to clean out blocked ventilation.
D. Relocate the machine to a cooler part of the building.

单项选择题Which of the following connectors is MOST commonly used for UTP cable?（）

A.RJ-45
B.RJ-11
C.LC
D.SC

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?（）

A. Network data cables are damaged.
B. Memory has become unseated.
C. The user has defragmented the hard drive.
D. Processor cooling fan is not functioning.

单项选择题After hardware upgrades have been installed, the technician boots the computer system. Nodisplay output is observed but a beeping is heard from the computer. Which of the following is the MOST likely issue?（）

A. Hard drive cables are not connected.
B. BIOS chips are not seated properly.
C. The power supply is not functioning.
D. Video card is not seated properly.

单项选择题A technician needs to upgrade the memory in a laptop. Which of the following memory typeswould be the correct type?（）

A.RIMM
B.DDR RAM
C.SDRAM
D.SODIMM