REQUEST system的用法和样例：
例句
- A knowledge base with self-contained functions and knowledge can consumedly improve efficiency and accuracy of a question answering system.
一个功能和知识完备的知识库能够大大提高问答系统的效率与准确率。 - We conclude with some yet unsolvable but quite interesting problems to study in the future to build a complete opinion QA system.
最后我们总结目前的实验结果，并提出一些相当有趣的议题，以供未来研究，进而实现一个完整的意见问答系统。
