When the sled had been accelerated to its top speed of 10 kilometres per second, laser and pyrotechnic devices would be used to separate the cone from the sled.是什么意思_When the sled had been accelerated to its top speed of 10 kilometres per second, laser and pyrotechnic devices would be used to separate the cone from the sled.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句