speck|specks

他的衬衫上沾了一个小污点。

There's a tiny ___speck on his shirt.

她的黑色毛衣上有几粒白色的小斑点。

There are a few white ___specks on her black sweater.

她的白衬衫上有一个小污点。

There's a tiny ___speck on her white shirt.