watermelon是可数名词吗

　　The pulp of this watermelon is too spongy.

　　这西瓜瓤儿太肉了。

　　The prospects of this year's watermelon market are good.

　　今年的西瓜市场看好。

　　This watermelon is really sweet!

　　这西瓜好甜哪！