笔者通过阅读文献与查询后发现，目前关于学习空间的研究还不太成熟，仍处于初级阶段，大多数学习空间项目研究的场所主要针对各类高校展开，相关的学术研究文献数量也不算多；...

According to Marin Joos’ The Five Clocks, phraseology can be divided into five levels, frozen, formal, consultative, casual and intimate on the basis of degree in formality. Formal English is used for public addresses such as lectures or s...