The weather turned out to be fine yesterday. I _____ the trouble to carry my umbrella with me. A. should have taken B. could have taken C. needn’t have taken D. mustn’t
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