volume positioning

例句：

1. 1.The volume of the book is 200 pages.
   这本书的页数是200页。
2. 2. The volume of data has increased significantly.
   数据量大幅增加。
3. 3. The volume of the new library is twice that of the old one.
   新图书馆的容量是旧图书馆的两倍。