答案:解: R=5, AB=4, BC=5-3=2AB段: BBB4000GyL2BC段: BBB2000GxL3CD段: B5000B0B10000GySR2DE段: B2B4B4000GyL3EA段: B3000B4000B6000GxSR4AB段: B4B2B40000 GxL1BC段: BBB20000GxL1CD段: B0B20000B20000GySR1DE段: BBB30000 GyL4EF段: BBB80000 GxL3FA段: BBB30000GyL2解: R=25, AE=25-15=10, DE=20AB段: B0B25000B25000GySR1BC段: B45B15B45000GxL3CD段: B20000B15000B30000GySR3DE段: BBB20000GxL1EA段: BBB10000GyL 2⏺