On Friday officials raised the alert level at the plant from four to five on a seven-point international scale of atomic incidents.

周五，官方将本次事件的警报级别从四级提高到五级，而核事故的国际标准仅有七级。

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Design and make a set of computer time scale experiment system on 82B Lab desk, include four phase time eletronic level and two phase working pulse.

在8 2 B型计算机实验台设计制作出一套计算机时标实验系统，包括四相节拍电平及两相工作脉冲，利用此时标系统可组合出计算机所需要的各种时序信。

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The World Health Organization on Monday raised its alert level from three to four on its six-level scale.

CNN: World battles swine flu as death toll rises

The move from level three to level four on the WHO's six-level threat scale means the world body has determined the virus is capable of significant human-to-human transmission -- a major step toward a flu pandemic, said Dr. Keiji Fukuda, the agency's assistant director-general.

CNN: The story

The International Atomic Energy Agency has classified the Tokaimura accident, which was the worst in Japanese history, as level four on its seven-point scale, making it the world's most serious since the level-seven disaster at Chernobyl in 1986.

ECONOMIST: All over in a flash