Yahoo香港字典 搜尋

搜尋結果

1. Oxford Dictionary

   catalyst

   • IPA[ˈkatəlɪst]

   英式

   • n.
     a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change；a person or thing that precipitates an event

   • noun: catalyst, plural noun: catalysts

2. • 釋義

   n.

   名詞

   • 1. a substance that increases the rate of a chemical reaction without itself undergoing any permanent chemical change chlorine acts as a catalyst promoting the breakdown of ozone
   • ▪ a person or thing that precipitates an event the prime minister's speech acted as a catalyst for debate
3. • 更多解釋

   catalyst

   • IPA[ˈkadləst]

   美式

   • n.
     a substance that increases the rate of a chemical reaction without itself undergoing any ... chlorine acts as a catalyst promoting the breakdown of ozone

   Oxford American Dictionary