● Display units，printers are （73) device. （73) A.inp t B.o tp tC.storage D.comm nic tion

● （75） are designed to manage large bodies of information. （75)A. I／O ports B. Printers C

● （74) is the foundation on which applications are built. 74) A.User B.Display C.Printer D

Pre－sequences are a fundamental unit of conversational structure.（)

● （72)are used for backing up large amounts of data. （72)A. Keyboard B. Printer C. Disk D.

●（71) devices are interface of man and machine.（71) A． I／O B．Memory C．Disk D．Printer

—They are testing the 3D printer. Don’t you come