社区在公园里埋下了一个时间胶囊，里面装有当地孩子们写给未来的信。

The community buried a ___time-capsule in the park containing letters from local children to the future.

这个老式照相机就像一个保存20世纪摄影技术的时间胶囊。

This vintage camera serves as a ___time-capsule preserving 20th century photography techniques.