Question

Thomas Alva Edison didn’t “invent” the light bulb, but rather he ______ a 50 –year –old idea, which is not well –known.

A．improved upon

B．take down

C．put up

D．break away

Answer 1

       A   

      题意：鲜为人知是的，爱迪生并没有发明灯炮，而是在其50年前的发明上改进了电灯泡（把灯丝寿命延长到13.5小时）。improve on/upon超过，改进；take down把……拆卸开；put up张贴，搭建；break away摆脱。