28. (1) Other gardeners have adopted a system called xeriscaping. (2) The approach aims to make the most of available water and sunlight in a self-sustaining way by recycling materials. (3) In California, water shortages caused by over-use are so acute that some gardeners have resorted to dyeing their lawns green. (4) The system involves grouping plants according to their watering needs and concentrating on drought-tolerant plants. (5) In Australia, however, another system called permaculture was pioneered by Bill Mollison.
(A) 31452
(B) 13452
(C) 21543
(D) 54321

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統計: A(6), B(3), C(5), D(0), E(0) #802526