The train has arrived. It arrived half an hour ago.

火车已经到了。它是在半小时前到的。

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The film began half an hour ago.

电影开始已经有半个小时了。

youdao

Soon conversation is flowing as if everyone is old friends, rather than the complete strangers they were only half an hour ago.

BBC: Vive l����volution in Paris

The atmosphere there was completely calm, and they've been seen by our embassy doctor, they're not suffering any obvious physical ill-effects from this at all, and half an hour ago, when I spoke to Peter Low, his wife and son were sleeping.

BBC: Breakfast with Frost

The two Presidents signed the agreement about an hour and a half ago down at the palace in Kabul.

WHITEHOUSE: Via Conference Call