根据短文内容，完成下列句子。

    Watermelon is a delicious fruit. We call it watermelon because it is mostly water. In fact it is 92% water. It's usually round and "green on the outside. When you cut a watermelon, it's red or yellow inside. Sometimes there are black seeds(种子) inside and sometimes the watermelon is seedless(无籽的).

    Watermelons are grown all over the world. The largest producer of this fruit is China. More watermelons are grown in China than anywhere else in the world. Many people like to eat watermelon, especially(特别) on a hot summer day!