题目内容
16.An egg sinks to the bottom if you drop it into a glass of ordinary drinking waterbut what happens if you add salt?The results arc very interesting and can teach you some fun facts about density(密度).
What you'll need:
*One egg*Water*Salt*A tall drinking glass
Instructions:
Pour water into the glass until it is about half full.
Mix in lots of salt (about 6 tablespoons).
Carefully pour in plain water until the glass-is nearly full (be careful not to mix the salt water with the plain water).
Gently lower the egg into the water and watch what happens.
What's happening?
Salt water is denser than ordinary tap water.The denser the liquid is,the easier it is for an object to float in it.When you lower the egg into the liquid it drops through the normal tap water until it reaches the salt water,at this point the water is dense enough for the egg to float.If you were careful when you added the tap water to the salt water,they will not have mixed,enabling the egg to amazingly float in the middle of the glass.
21.Which of the following is the CORRECT order?B
①Mix in lots of.salt.
②Gently lower the egg into the water.
③Carefully pour in plain water until the glass is nearly full.
④Pour water into the glass until it is about half full.
A.④②①③B.④①③②C.①④③②D.③④①②
22.What will happen if you drop an egg into a glass of water with about 6 tablespoons of salt?A
A.It will float in the water.
C.Nothing will happen.
B.It will sink to the bottom.
D.The result is not known.
23.Why can the egg float in the water according to the passage?C
A.Because ordinary tap water is denser than salt water.
B.Because ordinary tap water is as dense as salt water.
C.Because'the denser the liquid is,the easier it is for an object to float in it.
D.Because the more the liquid there is,the easier it is for an object to float in it.
分析 将鸡蛋放在普通的水里它会沉下去,那如果我们不断往水里加盐会发生什么样的情况呢?一起来看看这个有趣的实验吧.
解答 21-23.BAC
21题答案:B 细节理解题.根据文章中的"Instructions"部分可知答案为B.
22题答案:A 细芾理解题.根据文章最后一段的"…at this point the water is dense enough for the egg to float."(在这个点水的密度足够大可以使鸡蛋浮起来)可知答案为A.
23题答案:C 细节理解题.根据文章最后一段第一句话中的"…the denser the liquid is,the easier it is for an object to float in it."(液体的密度越大,在液体里的物体就越容易漂浮)可知答案为C.
点评 本文是一篇科教类阅读,题目涉及多道细节理解题,做题时结合原文和题目有针对 性找出相关语句进行仔细分析,结合选项选出正确答案.推理判断也是要在抓住关键句子的基础上合理的分析才能得出正确的答案.
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