I well remember our playground, which was behind the house. There were no trees, and the ground was as hard as stone.

我记得我们的操场，它就在房子后面。没有树，地面像石头一样坚硬。

" But surely, then, like other fossil wood, it must be as hard as stone, and cannot float? "

“但是，那么，像其他木化石一样，它肯定像石头一样坚硬，并且不能漂浮吗？”