不是
牙膏toothpaste是不可数名词，没有复数。但是可以说一管或者几管牙膏，比如A tube of toothpaste的意思就是一管牙膏。另外，他不仅有牙膏的意思，还可以翻译成洁齿剂。
举例拓展：Which brand of toothpaste do you use?你用什么牌子的牙膏?
I went out today and bought a tube of toothpaste.我今天出去买了一管牙膏。
Shaving supplies, toothpaste, and soap were found inside.
里面发现了剃须用品、牙膏和肥皂。
