11 There was a(n) ___ in the computer room yesterday. a revolution b process c explosion d stage 12 The company is well-known for the ___ of vacuum cleaners. a brochure b manufacture c tower d power 13 We asked the sales assistant to ___ how the machine works. a demonstrate b design c develop d invent 14 Don’t forget to ___ your work just in case something goes wrong with the computer. a back up b switch off c install d pay off 15 The new product is still in the first ___ of its development. a gadget b stage c ground d scheme 16 The technician didn’t take long to ____ the printer to the network. a think of b save up c hook up d go on 17 You can use a tablet without using a ___ or a mouse. a robot b programme c rocket d keyboard 18 What was their initial ___ when you told them what you’re designing? a curiosity b supply c research d react 19 She tried to stay calm when the paper got stuck in the ___. a headset b cellar c printer d business 20 Does your computer have a large ___? a device b innovation c screen d scanne 20 điểm lun giúp mik với đang cần gấp