问题
选择题
下列物质中，属于酸性氧化物，但不溶于水的是( )
A．CO2
B．SiO2
C．SO3
D．Fe2O3
答案
答案：B
酸性氧化物是指可以与碱反应生成盐和水的氧化物。Fe2O3碱性氧化物，排除；CO2、SO3是酸性氧化物，但均可溶于水。
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下列物质中，属于酸性氧化物，但不溶于水的是( )
A．CO2
B．SiO2
C．SO3
D．Fe2O3
答案：B
酸性氧化物是指可以与碱反应生成盐和水的氧化物。Fe2O3碱性氧化物，排除；CO2、SO3是酸性氧化物，但均可溶于水。
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| On Saturday morning there are a lot of people in Xiqing Park. Jim and David 1 at the gate of the park. They 2 to go into the park. D: Wow! So many cars and 3 here! There must be many people in the park. 4 go in and have a look. J: OK. Let's go. D: 5 can we buy tickets? Where's the ticket office? J: It's over there. Can you see the small window? D: Yes, I see it. 6 is a ticket? J: Look! It says two yuan for an adult (成年人), but one yuan 7 a school child. D: Hmm, it's cheap. We are school children. So we can 8 two tickets for one yuan. J: I'm afraid not (恐怕不行). We 9 have our school IDs. D: Oh, that's right! J: It doesn't matter (没关系). Let 10 go and buy two tickets for adults. | |||
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