英语翻译

英语翻译
1、Memory units may be characterized by their access and cycle times; memory access time may be defined as the length of time required to read a word from memory ,and memory cycle time may be defined as the minimum interval of time required between successive memory operations.
2、Packaged software refers to programs prewritten by professional programmers that are typically offered for sale on a diskette.There are over 12000 different types of application packages available for microcomputers alone.
3、Multimedia is the presentation of information using the combination of text,sound,pictures,animation,and video.Common multimedia computer applications include game,learning software,and reference materials.Most multimedia applications include predefined associations,known as hyperlinks ,that enable user to switch between media elements and topics.、
帮我翻译一下这3句话吧.