A wild duck (Anas platyrhynchos) of which the male has a green head and neck. Most domestic ducks descend from the mallard.

一种野鸭（绿头鸭），其雄鸟具有绿色的头和颈。大部分驯化了的家鸭都是绿头鸭的后裔。

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He had to duck his head to get through the low doorway.

他只得把头低下才能通过那低矮的门道。

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The mother duck pats him on the head.

母鸭轻拍着他的头。

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You can't duck your head and deliver a forcible blow with your helmet.

WSJ: NFL could eliminate tuck rule

Bend your knees and duck down, rolling your head in a 'U'shape under the punch from 'inside' to 'out.

BBC: DEFENCE

That would leave a brief lame-duck session after the elections as the only opportunity to head off the cuts before they take effect, and nobody is counting on that happening.

FORBES: Connect