Di guo de shi yan : Di guo de shi yan/ Mei guo fa zhi yan jiu/ Zhong guo shi yan : Zhong guo hua shi yan jiu/ Zhong guo suo de shui yan jiu/ Zhong guo cheng shi yan jiu / Zhong guo de shi jiao. Zhong guo li shi yan jiu fa/ Zhong guo shi xue shi yan jiu/