参考答案：专家预测，在21世纪，交通运输技术将有很多革新。//我们现有的各种交通工具今后仍将被广泛使用，//但其设计、材料和技术将会有很大变化。

解析：[听力原文]
According to experts, we can expect many changes in transportation technology in the twenty-first century. All the forms of transportation we use today will still be popular, but they will be very different in design, materials, and technology.