50. (2017·全国卷Ⅱ，64) It took three years to complete and was built
2023-11-15冠词练习
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.
50. The
