我们计划在12月去滑雪。

We plan to go skiing in ___December.

玛丽·约翰逊（2020年12月）是一位慈善家。

Mary Johnson ___Dec. 2020 was a philanthropist.

请在提交前检查12月的文件是否已签署。

Please check if the ___December document has been signed before submission.