答案：C

本题如选A项，其句型应为：What excited us Chinese greatly was that...。如选D项，应改为：As excited us Chinese greatly，Liu Xiang，...。B项中的that只能引导主语从句，不在句中作任何成分。如选B项，句中则缺少主语。本题中It为形主语,that引导的从句为真正的主语。