I was in school thirty years ago. We didn't have computers. Now

I was in school thirty years ago. We didn't have computers. Now they are available almost everywhere on campus, (compound-complex sentence)
【正确答案】：When I was in school thirty years ago, we didn’t have computers, but now they are available almost everywhere on campus.
【题目解析】：根据以上三个单句的关系，我们将其第一句处理为时间状语从句When，把第二句和第三句处理为主句。第二句和第三句我们用but来连接，表示以前没有电脑，但是现在校园中电脑随处可见。