文勇的新托福黄金&ccedil

upperpaleolithicpeoplerarelydepictedhumanfiguresinthe

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Unformatted text preview: ts, called hyper accumulators, can concentrate minerals at levels a hundredfold or greater than normal. ■ A survey of known hyper accumulators identified that 75 percent of them amassed nickel, cobalt, copper, zinc, manganese, lead, and cadmium are other minerals of choice. ■Hyper accumulators run the entire range of the plant world. ■ They may be herbs, shrubs, or trees. ■ Many members of the mustard family, spurge family, legume family, and grass family are top hyper accumulators. Many are found in tropical and subtropical areas of the world, where accumulation of high concentrations of metals may afford some protection against plant­eating insects and microbial pathogens. 13. Look at the four squares [■] that indicate where the following sentence could be added to the passage. 184 Mail@liuwenyong.com 在在在在在在 www.liuwenyong.com 在在在在在在在在在在在在在在在,在在在在在在在在在在 Certain minerals are more likely to be accumulated in large quantities than others. Where could the sentence best fit? 14. Directions: An introductory sentence for a brief summary of the passage is provided below. Complete the summary by selecting the THREE answer choices that express the most important ideas in the passage. Some answer choices do not belong in the summary because they express ideas that are not presented in the passage or are minor ideas in the passage. This question is worth 2 points. Plants need to absorb certain minerals from the soil in adequate quantities for normal growth and development. ● ● ● Answer Choices ○Some plants are able to accumulate extremely high levels of certain minerals and thus can be used to clean up soils contaminated with toxic levels of these minerals. ○Though beneficial in lower levels, high levels of salts, other minerals, and heavy metals can be harmful to plants. ○When plants do not absorb sufficient amounts of essential minerals, characteristic abnormalities result. ○Because high concentrations of sodium chloride and other salts limit growth in most plants, much research has been done in an effort to develop salt­tolerant agricultural crops. ○Some plants can tolerate comparatively low levels of certain minerals, but such plants are of little use for recycling nutrients back into depleted soils. ○Mineral deficiencies in many plants can be cured by misting their roots with a nutrient solution or by transferring the plants to a soilless nutrient solution. 185 Mail@liuwenyong.com 在在在在在在 www.liuwenyong.com 在在在在在在在在在在在在在在在,在在在在在在在在在在 在在在在在 1.○2 2.○2 3.○2 4.○2 5.○3 6.○1 7.○4 8.○4 9.○1 10.○3 11.○4 12.○2 13.○1 14.○1, 2, 3 186 Mail@liuwenyong.com 在在在在在在 www.liuwenyong.com 在在在在在在在在在在在在在在在,在在在在在在在在在在 在在在在 在在在在在在 在在在在在在在在在在在在在在在在在在在在在在在在在在在...
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This note was uploaded on 09/17/2013 for the course LANGUAGE 13DL208 taught by Professor Wang during the Fall '13 term at East China Normal University.

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