pea可数还是不可数

例句：

The tumour had shrunk to the size of a pea.

肿瘤已缩小到豌豆大小。

Pea pods burst open when overripe.

豌豆过熟就会爆裂。

Each pea and peach on the beach can be reached by the peacock.

海滩上的每一颗豌豆和桃子孔雀都能触及。