The specimens may not have glowing combustion that persists for more than 30 seconds after the second removal of the test flame.

没有任何试片在第二次测试火焰移开后燃烧持续超过30秒钟。

youdao

The specimens may not have glowing combustion that persists for more than 60 seconds after the second removal of the test flame.

没有任何试片在第二次测试火焰移开后燃烧持续超过60秒钟。

youdao

It says the flash of light comes not from any type of combustion -- as we typically think of explosions -- but rather by the glowing molten rock at the impact site.

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