没有坚果钳，很难敲开巴西坚果的壳。

It's hard to crack the ___shell of a Brazil nut without a nutcracker.

我在森林小径上发现了一个小小的蜗牛壳。

I found a tiny snail ___shell on the forest path.

她从海滩带回的最喜欢的纪念品是一袋五彩斑斓的海贝壳。

Her favorite souvenir from the beach was a bag of colorful sea ___shells.