Which thematic progression pattern has been used in this paragraph? Hemp’s environmental credentials are indisputable. It grows better in organic systems than in conventional ones. It smothers weeds and controls pests, clearing the land for other crops. It improves the structure of the soil, with strong roots to prevent erosion. If processed in the field, it returns nutrients to the land and purports to ‘clean up’ soil contaminated with heavy metals. It is one of a minority of textile-fibre crops that can be grown in temperate climates. So why, given its potential, is so little hemp used today? (New Internationalist, June 1998, p. 14)
举一反三
- mini-talk 2 A: Organic farming can reduce soil erosion. B: Organic crops produce lower yields. C: Organically grown food tastes strange. D: Organic farming is better for the environment.
- When the field surface is covered by gravel, soil erosion caused by rain and strong winds can be effectively prevented.（ ）
- What is the main problem caused by the usual way of plowing A: The crop’s blooming period is delayed. B: The roots of crops are cut off. C: The top soil is seriously damaged. D: The growth of weeds is accelerated.
- which materials can be used to increase soil pH A: Ferrous sulfate B: Quick lime C: Plant ash D: Organic fertilizer
- Which of the following is not a result of Industrializing agriculture (or, “chemicalization” of agriculture) A: Water shortage B: Land pollution C: Financial failure D: Soil erosion