沙滩上发现了一个空壳。

A ___hollow shell was discovered on the sandy shore.

他把那本深红色皮革装订的书带到了他在森林里的藏身处，一棵树干中空的老橡树，他曾独自在那里玩耍。

He had taken the dark red leather-bound book to his hideout in the forest, an old oak tree with a ___hollow trunk, where he used to play alone.

这座古老的木雕雕像内部出人意料地是空的。

The ancient wooden statue was surprisingly ___hollow inside.