A根据以下材料，回答21-35题LosAngeles has planted 2,000 rubber trees down the middle of one of its mainstreets. These trees do not 21 rubber. They are,22,made ofrubber. Mr. Joe Dynamo, a spokesman for Los Angeles 23 council, explained the reasons. He said: "These 24 are representative of our virtualsociety. We have polystyrene grass on our golf 25. We have non-milk powder 26 our coffee. We 27 copies in plastic of old wooden furniture.We have fiberglass tombstones.28__________ shouldn′t we have trees made of rubber? "At 50 miles an hour,29 motorist will see any difference. ourpreservation 30 will be lower. You give the trees anannual rinse(清洗 with detergent, 31 them off twice a year. We 32 a lot of money becausetransplanting, pruning, weeding leaf-collection are all 33. wehave a 60-year 34 guarantee on each plant. This isrationalization at 35best."[单选题] 第21题答案是（??） 查看材料A.invent
