who were they invented by?这个句子的结构是什么?by是怎么回事?急,谢谢帮助.

who _______were potato chips invent? Who were they according to what they said? people who invent many things 意思是、 Who ____ the electric lights?(invent) some people hurt themselves when they were watching a sports programme.who were they? . Computers were a great __________(invent) in the 0th century. 2. They were too tired1. Computers were a great __________(invent) in the 0th century.2. They were too tired to walk any __________(far).3. __________(bind) affects about 45 million peop Who invented the aeroport?when were they born? they even didn't know who you were.how______they___(believe) people were f _but they tried to save the people who were trappe填什么? when were electric slippers invented?who were they invented by?what are they used for?什么意 who were computers invented by?when were computers invented?how were computers invented?what are they used for? who _______(invent) basketball in 1891?【【原型吗?】】 do you know who--------（invent） the tv set? If I were an inventor,I would invent many useful things to lighten my parents' pressure from work,If I were an inventor,I would invent many useful things to lighten my parents' pressure from work,so that they can have more time for me.Firstly,I would who is this service helping在he's just not that into you里面的一句台词 一个女的独白：I have a question,why did they invent caller id?it's like,who is this service help 被动语态怎么改特殊疑问句?例如：I was hit by him.对by him 划线提问,要怎么改?再帮我看道题吧..Could you tell me( A whom were lights inventedB that lights were inventedC who lights were invented byD by who lights are invent When did they invent the plane?改为被动语态. the bodies of those who have failed,were they piled one atop another,would cast a shadow down为什么是第二句是were they ,不是were