单项选择题 A technician is trying to install a previous-generation expansion card into their new laptop.However, the card refuses to fit into the expansion slot. Which of the following is MOST likely the reason?（）

单项选择题 A user’s OS has become corrupt, and the user would like to restore the PC back to when they first bought the machine. Which of the following would be the BEST choice?（）

单项选择题 Which of the following ports is MOST likely used for high-end graphics cards?（）