单项选择题 A technician is checking on a printer that is frequently jamming. The jams always consist ofmultiple papers becoming stuck. The paper in the printer was just reloaded this morning. Which of the following is the MOST likely reason for the jams?（）

单项选择题 A user requires more storage space on their computer. After a technician installs a second IDE drive in the computer, the system will not recognize that there are any hard drives installed. Which of the following is the MOST likely cause of the problem?（）

单项选择题 Which of the following wireless technologies is backward compatible to receive all bands ofwireless communications?（）