贝壳的英文单词怎么写?

问题一：贝壳英文是什么 贝壳
英语：
n. shell ; conch ; cowry
misc. mother of pearl
双语例句：
退潮时我们可以在沙滩上捡贝壳。
When the tide is out,we can pick up some shells on the sand.
她把贝壳串在一起，然后戴在脖子上。
She threaded the shells together and wore them round her neck.
退潮后沙滩上留下了许多贝壳。
When the tide had ebbed away,the shells were left on the sand.

问题二：贝壳怎么用英语说？ 贝壳 shell

问题三：捡贝壳用英语怎么说 ??collect shells