I chose a sand dollar because it comes from the ocean.

我选择沙海胆，因为它来自海洋。

The Sand Dollar or Holy Ghost Shell is one of the most unusual specimens of Marine life.

沙美元或圣灵板是海洋生物最不寻常的标本之一。

Most of the meteors are about the size of a grain of sand, but some can be as large as a silver dollar.

大部分流星只有沙粒大小，但有一些可以大到象一块银元。