1.at the end of在...结束时
This is the draft of a declaration that will be issued at the end of the aforementioned U.N. conference.
这是将在上述联合国会议结束时发布的宣言的草稿 。
2.at once马上
Please be so kind as to see to it that all the alterations are made at once!
请注意所有变更必须马上完成!