pea可數還是不可數

例句：

The tumour had shrunk to the size of a pea.

腫瘤已縮小到豌豆大小。

Pea pods burst open when overripe.

豌豆過熟就會爆裂。

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

海灘上的每一顆豌豆和桃子孔雀都能觸及。