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化学与生产、生活密切相关。 （1）人类生活离不开空气。北京市政府为防止空气污染采取措施，要求各单位用煤必须使用低硫优质煤，这种做法能有效减少排放的气体是_______；燃煤过程中，生成该气体的化学方程式为_______。 （2）在生活中，缓慢氧化的例子很多，以下属于缓慢氧化的有（填序号）_______。 ①蜡烛燃烧，②动植物的呼吸，③食物的腐烂，④酒和醋的酿造，⑤火药爆炸，⑥钢铁生锈，⑦农家肥料的腐熟。 （3）硅是信息技术的关键材料，高温下氢气与四氯化硅（SiCl 4 ）反应可制得高纯度的硅，同时生成氯化氢。该反应的化学方程式为_______。 （4）录像用的高性能磁粉，主要材料之一是由三种元素组成的化学式为Co x Fe (3-x) O (3-x) 的化合物，已知氧为-2价，钴（Co）和铁可能呈现+2价或+3价，且上述化合物中，每种元素只有一种化合价。则x值为_______，铁的化合价为_______。 （5）肾病患者需要食用低钠盐的食品。目前，市场供应的低钠盐多为苹果酸钠盐（C 4 H 5 O 5 Na）。每日食用5g苹果酸钠盐，人体摄入的钠元素质量仅为等质量食盐中钠元素质量的_______。 A. 18.7%B. 26.7%C. 37.5%D. 43.1%
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【简答题】"It started with casual Fridays and got out of hand," says June Webb, a fashion consultant in Alexandria. (Para. 4) Q: What does June Webb mean in his quotation?
【单选题】What does the woman say she will hand out?
A.
An outline
B.
A handbook
C.
A contract
D.
A memorandum
【单选题】What does the author mean by saying “ the boy who has the genius ... try his hand at the broom ” (Line 6-8, Paragraph 1)?
A.
A promising young man will do less important work when needed.
B.
A wise starter will do whatever necessary so as to keep his position.
C.
Anyone who wants to be successful should take some trivial work first.
D.
The newest comers ready to sweep out the office will be successful.
【单选题】What does the speaker say is the easier thing we could do ?
A.
Allow kids to learn at their own pace.
B.
Encourage kids to learn from each other.
C.
Organize kids into various interest groups.
D.
Take kids out of school to learn at first hand.
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