—What’s ______ most useful invention in the 20th century?

What's ___ most vseful invention in the 20th century?--___co what's the most useful invention?我有急用. what do you think is the most useful invention in the world 一个英语冠词选择What's the most useful invention - _____computer,I t What,in your opinion,is the most significant invention in th The computer is ______ useful invention in the modern wored. What are the most important things in this century?______ __ 连词成句 What do useful you think invention is the fourth most What do you think is the most useful invention?这句中do you thi Do you think what invention is the most useful 这句话对吗 the article which_______ most useful will be published in th 英语翻译Until late in the 20th century ,most Americans spent tim