Or is it that the singular should be changed: one "serie," or "serum," just like the singular of "sheep" should be "shoop."
या एकवचन की परिवर्तित किया जाना चाहिए:एक "सिरी,या",सीरम", जैसे "शीप" की एकवचन "शूप" होना चाहिये