spacing in the row

例句：

1. 1.The teacher asked the students to pay attention during the lecture.
   老师要求学生们在讲座期间保持注意力集中。
2. 2. The book has a spacing of 10 pages between each chapter.
   这本书每章之间有10页的间距。
3. 3.The distance between the two cities is about 500 kilometers.
   两座城市之间的距离大约是500公里。