问题
填空题
水是生命之源，我们应该节约水、爱护水资源．
（1）水是由______两种元素组成．
（2）日常生活中通过______可以降低水的硬度．
答案
（1）由水的水组成元素可以看出，水是由氢氧两种元素组成的．
故答案为：氢氧．
（2）硬水水加热后会使一些离子沉淀下来，从而减低其硬度，往往以水垢的形式出现．
故答案为：煮沸．
搜题请搜索小程序“爱下问搜题”
水是生命之源，我们应该节约水、爱护水资源．
（1）水是由______两种元素组成．
（2）日常生活中通过______可以降低水的硬度．
（1）由水的水组成元素可以看出，水是由氢氧两种元素组成的．
故答案为：氢氧．
（2）硬水水加热后会使一些离子沉淀下来，从而减低其硬度，往往以水垢的形式出现．
故答案为：煮沸．
Two brothers worked together on a farm. One was married and had a large 51 . The other had no wife yet. Although they lived in different houses, they shared everything they got from their farm. One day, the single brother said to himself, “It’s not 52 that we share all the rice. I’m 53 and I need less than my brother.” So, every night he took a bag of rice from his store-room and 54 across the field 55 their houses, putting it into his brother’s store-room. At the same time, the married brother thought, “It’s not fair to share all the rice. I’m married and I have my wife and children to 56 me when I am 57 . However, my brother has no one to take care of his 58 .” So, each night he also took a bag of rice and put it into his brother’s store-room. Several months passed by. They found 59 strange that their rice never became less. Then, one dark night the two brothers ran into each other. Slowly they began to understand what was happening. Their bags fell onto the ground and tears 60 their eyes at once.
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