It is a colourless, odourless and tasteless gas, slightly heavier than air.
It is a colourless, odourless and tasteless gas, slightly heavier than air.
它是一种无色、无溴、无味的气体，比空气稍重。
It is a colourless, odourless and tasteless gas, slightly heavier than air.
它是一种无色、无溴、无味的气体，比空气稍重。