【单选题】听力原文:M: My typing isn't dark enough and the paper doesn't look good. W: Why not change the typewriter ribbon and see if that helps? Q: What does the woman advise the man to do? (19)
【单选题】A student carries out an experiment to find how fast 3 cm pieces of magnesium ribbon dissolve in10 cm 3 samples of sulfuric acid at different temperatures.Which piece of apparatus does the student not...