A vacuum pump pulled the products of combustion through the pipe and exhausted them outside at the end of the run . 一真空泵把燃烧的产物推进管子,在管道行程的末端将其释放掉。
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A vacuum pump pulled the products of combustion through the pipe and exhausted them outside at the end of the run . 有一个真空泵把燃烧的产物推进管子,在管道行程的末端外面使这些产物彻底烧尽。