单项选择题 Mike, a technician, is installing a wireless router for a client. Which of the following is MOST important when installing a wireless router?（）

单项选择题 Computers on the network are frequently infected with viruses, malware, worms and Trojans.Which of the following should Mike, a technician, update automatically to prevent future problems?（）

多项选择题 A printer is consistently printing random characters on every page. Which of the following should be done? （）(Select TWO).