gravity preparation

例句：

1. 1. The engineer made a gravity preparation for the construction site.
   工程师为工地做了重力准备。
2. 2.The team leader prepared a gravity preparation before the meeting.
   会议前，团队领导准备了重力准备。
3. 3. The scientists conducted a gravity preparation to study the effects of gravity on objects.
   科学家们进行了重力准备，以研究重力对物体的影响。