题目

 Na2S2O3是重要的化工原料，用途很广，其还原性较强，在溶液中易被Cl2氧化成SO，常用作脱氯剂，主要用于治疗氰化物中毒。工业上可利用反应Na2CO3＋2Na2S＋4SO2===3Na2S2O3＋CO2制取Na2S2O3，下列说法正确的是( ) A. Na2S2O3只有还原性 B. 氧化产物与还原产物的物质的量之比为1∶2 C. 每生成1 mol Na2S2O3，转移4×6.02×1023个电子 D. 每吸收4 mol SO2就会放出22.4 L CO2The world would be a very different place if someone hadn’t invented the lift. There would be few, if any, high-rise buildings because people would refuse to climb many stairs. By the time workers reached their offices on the top floors of a tower building, it would be time to go home – if they were not too tired for the long walk down！The first lift that we know about was used by the Greek scientist, Archimedes, in about 230 BC. It was a simple place that could be pulled up and down with a rope. A lift like this was used much later in the 12th century by priests who lived on top of a mountain at Metereo in Greece. Because they were afraid of killers, the priests had not built any stairs up the mountain. The only way up was by lift, which priests worked from the top of the mountain.A few hundred years later, a Frenchman, Villayer, invented a ‘flying chair’ which used a rope and a place. A number of rich people had these ‘flying chairs’ built in their homes, including Queen Anne of England in Windsor Castle and Louis XVI of France at Versailles. Unluckily, Louis’ daughter was badly hurt when using one of the chairs, and Villayer ran away, afraid that he would be punished.The main problem for lift engineers was that either humans or animals were needed to pull the ropes. This problem was not worked out until the discovery of steam power. But even steam powered lifts were not always safe because they also used ropes which sometimes broke. If the rope broke - which it sometimes did - the lift fell to the ground and people in it were killed or hurt. This problem worked out in 1854 when an American, Elisha Otis, invented something which stopped the lift from falling if the rope broke. At first Otis lifts were used only in factories, then in 1857 he built one in a large New York store. Now lifts use electric power and are completely safe. They also travel very quickly. Some lifts travel faster than 60 kilometers an hour.小题1:The writer thinks that lifts are important today because __________.A．people like playing on themB．they are the best way of using steam powerC．we need them for tall buildings D．workers are lazy小题2:The 12th century priests had a simple lift instead of stairs because ___________.A．they thought the stairs were brokenB．they liked having stairs and a liftC．the lived at the bottom of a mountainD．they were afraid of killers小题3:Villayer thought he would be punished because ____________.A．poor people could not afford his ‘flying chairB．someone was hurt in one of his ‘flying chairs’ C．his ‘flying chair’ did not work at allD．he ran away with Louis XVI’s daughter小题4:Steam power meant that ________  .A．they did not need a living thing to pull the ropesB．Elisha Otis could invent a lift that would not fallC．the rope always brokeD．they could use lifts in factories