试题与答案

2010年,我市遭受了严重的旱灾. (1)人工增雨是缓解干旱的重要手段,干冰可用

题型:问答题

题目:

2010年,我市遭受了严重的旱灾.

(1)人工增雨是缓解干旱的重要手段,干冰可用于人工增雨.撒在云层中的干冰升华时______(填“吸收”或“放出”)热量,使空气中的水蒸气迅速凝结成水滴形成雨.

(2)施用磷肥可以提高农作物的抗旱能力,其中一种磷肥的主要成分是磷酸二氢钙[Ca(H2PO42],该化合物中磷元素的化合价为______.

(3)硬水是指含有较多______(填写离子符号)离子的水.

答案:

(1)干冰是固态二氧化碳,升华时易吸收热量变成气体;

(2)根据化合物中正负化合价代数和为0可得:(+2)+[(+1)×2+x+(-2)×4]×2=0,可求出X=+5;

(3)硬水是含有较多钙镁离子化合物的水.

故答案为:(1)吸收(1分)    (2)+5(2分)   (3)Ca2+、Mg2+

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题型:阅读理解

根据对话内容,从对话后所给的选项中选出能填入空白处的最佳选项。选项中有两个为多余选项。

( In a restaurant)

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__Very good.    10   .

__yes, I’d like some mineral water, please.

__ OK. So that’ a green salad, fish and chips and mineral water.

__ Yes, that’s right.

A.Here you are.

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C.Right this way, please.

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