●ASCII is a 7－bit code used to represent numeric,alphabetic,and special printabl

●ASCII is a 7-bit code used to represent numeric，alphabetic，and special printable characters．It also includes codes for control characters，which are (75) .

(75) A．printable or displayable

B．not printable or displayable

C．not printable but displayable

D．printable but not displayable

B【解析】ASCII是一种7比特编码，它用来表示数字、字符和特殊的打印符号。它也包含控制字符的编码，这些编码不能够打印或者显示。