dead beat
筋疲力尽
A:Where is Tom?
A:汤姆哪去了?
B:He is in the bedroom and fallen asleep.
B:他在卧室睡着了。
A:What? It's only 9:00 p.m. now. Why today he went to bed so early?
A:什么?现在才晚上9点钟。怎么今天他睡得这么早?
B:He ran four miles and came back dead beat.
B：他跑了四英里路，回来时筋疲力尽了。
A:Oh, I see.
A：噢，知道了。