Blood vessels in the head tighten to stop the loss of body heat and then relax to let blood flow rise; that sudden rush of blood is what causes the headache.

头部的血管收紧以阻止身体热量的流失，然后放松让血液流动起来，血液的突然涌入是引起头痛的原因。

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Waving can mean welcome and farewell, whereas scratching your head may indicate that you are at a loss.

挥手表示欢迎和告别，而挠头则表示不知所措。

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The financial rescue plan passed by the US Congress is viewed as flawed but necessary to head off panic in financial markets and loss of confidence in the economy.

人们认为美国国会通过的金融纾困计划有缺陷，但对于防止金融市场中出现恐慌情绪、避免人们丧失对经济的信心，又是必要之举。

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It was the first "Senior Night" loss for Williams as a head coach, both at Kansas and at North Carolina.

NPR: No. 3 Duke Hammers North Carolina 69-53

Types of injuries which would be sent to the Royal Cornwall Hospital include chest pains, strokes, head injury with loss of consciousness, severe abdominal pain and all severely ill children.

BBC: West Cornwall Hospital

It was never clear whether his aim was to get negotiations started without too much loss of face or just to head off sanctions.

ECONOMIST: Iran and nuclear diplomacy: A yes or a no? | The