题目

常温下，浓度均为0.1mol/L的三种溶液：①CH3COOH溶液②NaOH溶液③CH3COONa溶液，下列说法中不正确的是（忽略混合前后溶液体积变化）（   ） A . 溶液的pH值：②＞③＞① B . 水电离出的c（OH﹣）：③＞①＞② C . ①和②等体积混合后的溶液：c（CH3COOH）+c（CH3COO﹣）=0.1mol/L D . ②和③等体积混合后的溶液：c（Na+）+c（H+）=c（OH﹣）+c（CH3COO﹣）The bicycle is one of the simplest yet most useful inventions in the world. What is most surprising is that it was not ___1__ earlier, although the great inventor Leonardo Da Vinci had drawn pictures for bicycles and also for flying machines and some other things. Those things were not produced___2___ long after he died.　　A person riding a bicycle uses ___3___ energy to make the bicycle move, and there is no pollution at all when you are riding. Even so, in developed ____4___, most people don’t travel to work by bicycle. It is not because the bicycles are expensive or people feel___5____ if they ride to work. It’s because __6___ cars on the roads becomes larger. It certainly becomes ___7___ to ride a bicycle. As a result, more people put their bicycles away and go to work ___8___ their cars cars, and in this way, the situation is made more serious.___9___ the best way to make riding safer and more popular is to create paths (开设通道) only for bicycles, and to make ___10___ so difficult and expensive for drivers to take their cars into the city that they will go back to use their bicycles. 【小题1】A．invent B．inventing C．invented D．to invent【小题2】A．before B．when C．since D．until【小题3】A．much B．quite a lot of C．very little D．many【小题4】A．world B．countries C．land D．earth【小题5】A．lucky B．glad C．sorry D．tired【小题6】A．the number of B．a number ofC．this kind ofD．all kinds of【小题7】A．safer B．more dangerousC．much dangerous D．safe【小题8】A．by B．in C．use D．drive【小题9】A．Hardly B．May be C．Perhaps D．Nearly【小题10】A．it B．them C．us D．that