Thomas Alva Edison didn’t “invent” the light bulb (灯泡), 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
Thomas Alva Edison didn’t “invent” the light bulb (灯泡), 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
A
句意：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。