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阿甘
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阿甘 asked in 科學地理學 · 1 decade ago

一些有關礦物的選擇題問題

24. In silicate minerals, tetrahedra may be coordinated to form ____________.

A. long one-dimensional chains

B. extensive two-dimensional sheets

C. massive three-dimensional frameworks

D. all of the above

29. The facets on cut gemstones most commonly represent ____________.

A. natural cleavage planes of the mineral

B. original crystal faces

C. neither cleavage planes nor crystal faces, but artificially cut planar surfaces

D. none of the above

9. Heating iron ores does not produce native iron unless done in the presence of ____________.

A. oxygen C. nitrous oxide

B. carbon dioxide D. methane

12. Which of the following is not an important ore of iron?

A. magnetite (iron oxide)

B. hematite (iron oxide)

C. pyrite (iron sulfide)

D. All of the above minerals are important ores of iron.

14. Which property of these ores (answer to question 13) causes them to be concentrated by magmas?

A. low temperatures of crystallization

B. high temperatures of crystallization

C. low density

D. high density

1 Answer

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  • 1 decade ago
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    24. In silicate minerals, tetrahedra may be coordinated to form ____________.

    A. long one-dimensional chains

    B. extensive two-dimensional sheets

    C. massive three-dimensional frameworks

    D. all of the above

    29. The facets on cut gemstones most commonly represent ____________.

    A. natural cleavage planes of the mineral

    B. original crystal faces

    C. neither cleavage planes nor crystal faces, but artificially cut planar surfaces

    D. none of the above

    9. Heating iron ores does not produce native iron unless done in the presence of ____________.

    A. oxygen

    B. carbon dioxide

    C. nitrous oxide

    D. methane

    12. Which of the following is not an important ore of iron?

    A. magnetite (iron oxide)

    B. hematite (iron oxide)

    C. pyrite (iron sulfide)

    D. All of the above minerals are important ores of iron.

    14. Which property of these ores (answer to question 13) causes them to be concentrated by magmas?

    A. low temperatures of crystallization

    B. high temperatures of crystallization

    C. low density

    D. high density

    No question 13

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