And this is usually done over catalysts, like an iron oxide catalyst or something.

经常还需要一些催化剂，像氧化铁催化剂或其它东西用。

youdao

And this is usually done over catalysts, like an iron oxide catalyst or something.

经常还需要一些催化剂，像氧化铁催化剂或其它东西用。

youdao