A watermelon is red inside and green outside.
西瓜内红外绿。
Oh, what a big watermelon!
喔唷，这么大的'西瓜！
The watermelon has gotten bad.
西瓜娄了。
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。