英语表达
I do not know (I don't know).
文本示例
文本：I don't know the answer.
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其他固定表达
The last straw
Good morning!
Salty
Can you help me?
Burn bridges
Kill two birds with one stone.
Me too!
See you!
Which bus should I take?
Piece of cake
I would like to order a pizza.
What time does the train leave?