50. (2017·全国卷Ⅱ，64) It took three years to complete and was built
分类: 冠词练习发布时间: 2023-11-15 17:20浏览量: 3
50. (2017·全国卷Ⅱ，64) It took three years to complete and was built using an interesting method. This included digging up the road，laying the track and then building a strong roof over ________ top.