double acting jack

例句：

1. 1. The double acting jack isused to lift heavy objects.
   双作用液压机用于提起重物。
2. 2. Thedouble acting jack isessential for the construction of buildings.
   双作用液压机对于建筑施工至关重要。
3. 3. The double acting jack was developedto improve efficiency in heavy lifting tasks.
   双作用液压机的开发是为了提高重型起重任务的效率。