EnglishQuestionMainframecomputerswereverylargeindeed,oftenoccupyingwholeair-conditionedrooms,employingfull-timetechniciansandrunonspecially-writtensoftware.Question:1.为什么用run不用running?2.为什么specially-written要用-

Question

English Question
Mainframe computers were very large indeed,often occupying whole air-conditioned rooms,employing full-time technicians and run on specially-written software.
Question:1.为什么用run不用running?
2.为什么specially-written要用-连接起来?
我怎么觉得是一个结果状语从句呀？
computer很大，结果就是要占很大的房间
为什么是做定语？
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并且我还要说的是：run的过去式式ran，过去分词式run
怎么可能和were并列呢？

Answer 1

1·often occupying whole air-conditioned rooms,employing full-time technicians 是两个非谓语动词（这里是动词ing形式）作前面computers的修饰成分,即定语.而run on specially-written software是作第二个谓语,与were 并列.
2·
副词+连字符+动词的过去分词,可以构成复合式形容词,如：a well-written composition,写的很好的作文.a over-cooked meal烧过了的饭