题目

在旁边葡萄园里，果农正在配制波尔多液。（1）果农分别向硫酸铜中加入沸水、生石灰中加入冷水，其中发生反应的化学方程式为_______。（2）用硫酸铜配制的农药波尔多液，可以防治葡萄生长中的病害。溶解硫酸铜时不宜用铁制容器，用化学方程式表示其原因：_______。 答案：【答案】CaO + H2O=Ca(OH)2 Fe + CuSO4 = FeSO4 + Cu 【解析】（1）生石灰与水反应生成氢氧化钙，反应的化学方程式为：CaO+H2O═Ca（OH）2；（2）波尔多液主要由硫酸铜和氢氧化钙混合配制而成，不能用铁制品盛放的原因是由于铁会与硫酸铜反应生成铜和硫酸亚铁，反应的化学方程式为：Fe+CuSO4=Cu+FeSO4。 　　Have you ever been ill?When you are ill, you must be unhappy because your body becomes hot, and there are pains all over your body．You do not want to work．You stay in bed, feeling very sad． 　　What makes us ill?The germs．(细菌) 　　Germs are everywhere．They are very small and you cannot find them with your eyes, but you can see them with a microscope．They are very tiny and there could be hundreds of them on a very small thing． 　　Germs are always found in the dirty water．When we look at dirty water under the microscope, we will se germs．So your parents will not let you drink dirty water． 　　Germs are not found only in the water．They are found in the air and dust．If you cut your finger, and if some of the dust goes into the cut, some of the germs will go into your finger．Your finger will become big and red, and you will feel painful．Sometimes the germs will go into all of your body, and you will have pains everywhere． (1) Which of the following is TRUE? [　　] A． If things are very, very small, they are germs． B． If things cannot be seen, they must be germs． C． Germs are only in the dirty water． D． Germs are everywhere around us． (2) What is the meaning of the underlined word tiny? [　　] A． very, very small B． very beautiful C． very big D． very dirty (3) Your parents do not let you drink dirty water because ________ [　　] A． you have not looked at it carefully． B． water cannot be drunk in this way． C． there are lots of germs in it D． water will make you ill (4) Which of the following is not true? [　　] A． Germs can be found both in the water and in the air． B． Germs can go into your finger if your finger is cut． C． If your temperature is not OK, there may be germs in your body． D． There are no germs in our bodies．