单项选择题 A user states that their laser printer prints black and white streaks about half an inch wide down the left side of every page. Which of the following components MOST likely needs replacing?（）

单项选择题 A user reports that their thermal wristband printer is printing barcodes that will not scan properly.Which of the following maintenance techniques would MOST likely resolve this issue?（）

单项选择题 Which of the following laptop components will MOST likely need replacing within the first threeyears of use?（）