Human activity is the main reason for this, the United Nations (UN) said.

联合国表示，人类活动是造成这一现象的主要原因。

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Acronyms are words formed from the first letter of several words (such as UN for United Nations).

首字母缩写是由每个单词的第一个字母组合而成的，比如un就是指united Nations。

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But Molyka wasn't at the UN headquarters in New York. Instead, she was participating in the annual Beijing Model United Nations last weekend at China Foreign Affairs University.

不过莫丽卡并不是在纽约的联合国总部。她参加的是上周在外交学院举办的一年一度的北京模拟联合国大会。

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Rice addressed the first session of the United Nations (UN) Women Executive Board.

WHITEHOUSE: Ambassador Susan Rice Addresses the United Nations Women Executive Board | The White House

Last week, Palestine filed a controversial application with the United Nations (UN) Security Council to become a UN member state, a move that is strongly opposed by the United States and Israel.

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Now a 57 state collective which includes every Islamic nation on earth, the OIC, currently headed by Turkey's Ekmeleddin Ihsanoglu, thus represents the entire Muslim umma (or global community of individual Muslims), and is the largest single voting bloc in the United Nations (UN).

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