When I returned there last April, the dragon's head has collapsed for unknown reason.

去年四月，当我回到那儿，这条龙的头部由于不明原因而倒塌了。

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A dragon like rock formation created from thousand years of erosion. When I returned there last April, the dragon's head has collapsed for unknown reason.

几千年的腐蚀创造而成了一条像龙的岩石形成。去年四月，当我回到那儿，这条龙的头部由于不明原因而倒塌了。

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For some unknown reason, many were discarded, often still intact, and thousands have been found all over the Near East.

由于一些未知原因，很多被丢弃的物品还是被完整地保存下来了，而在近东的各地有上千件这样的物品出土。

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For some unknown reason, it tries to force me to use Albany, NY as my departure airport for every search even though I do not live near Albany and have never flown in or out of the airport.

FORBES: Google Flights? Not Ready For Prime Time.

The Republicans, for some unknown reason, decided to pass on fully emulating that system year.

FORBES: Obama's Not-So-Secret Weapon: Will He Use It to Help Power His New Mandate?

Tobey Maguire, looking ever more costive and uncomfortable, returns as Peter Parker, who finds himself doubly transformed first into the crime-busting arachnid whom we know and revere, second into a black-suited alternative who revels in violence and, for some unknown reason, keeps breaking into dance moves.

NEWYORKER: Spider-Man 3