给出一组句子和相应的标签，建立一个文本分类器，并对新句子进行分类。
训练数据集：
“I love playing tennis.” -> “sports”
“I enjoy reading books.” -> “books”
“I prefer watching movies.” -> “movies”
测试句子：“I hate exercise.”
建立一个基于训练数据集的文本分类器，并使用训练好的模型对测试句子进行分类。

训练数据集：

- “I love playing tennis.” -> “sports”
- “I enjoy reading books.” -> “books”
- “I prefer watching movies.” -> “movies”

测试句子：

- “I hate exercise.”

分类结果：

- “I hate exercise.” -> "sports"