It involved Pullman turning ten Jackscrews.
2015年高考英语湖南卷 阅读理解 阅读B 选项
One man was assigned to operate each section of roughly 10 Jackscrews.
2015年高考英语湖南卷 阅读理解 阅读B 原文
To lift a big structure like the tremont hotel, pullman would place thousands of Jackscrews beneath the building's foundation.
2015年高考英语湖南卷 阅读理解 阅读B 原文