It’s seems amazing that at my age I am still fit enough to cycle 20 kilometres in an afternoon. [考点] 此句中的it是形式主语，真正的主语是后面的that从句。 [考例] It felt funny __________ (watch) myself on TV. 此句中的it是形式主语，真正的 主语是后面的watching myself on TV。

watching