第31题: [单项选择]A. That the participants are growing makes L.A, Bike Trains unique. B. That the length of the route ranges from 7 to 32kin makes L.A. Bike Trains unique. C. The profound meaning makes L.A. Bike Trains unique. D. Its early launch time makes L.A. Bike Trains unique. 参考答案:B 答案解析:[听力原文] What makes L.A. Bike Trains unique compared to other cities