And catalysts of higher activity should be developed to fit the new kind of circulating fluidized bed reactor, downer, for the FCC process.是什么意思_And catalysts of higher activity should be developed to fit the new kind of circulating fluidized bed reactor, downer, for the FCC process.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句