I'm done in and must rest here.
我累透了，必须在这休息一下。
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今天的几个句子还是有关表达疲劳的：1.Well,I have to admit I feel extremely tired.哦，我得承认我觉得累极了。2.Well, I should say the lecture is exhausting.啊，我得说那演讲叫人精疲力竭。3.I must have tired myself out.我一定是太劳累了。