2 goes to c 1 goes in to b and 3 goes in to a hope you get them correctly
I have just done this in chemistry and i think the answer is B. A substance thst speeds up a reaction, and is not used up. Hope this helps:)
This is an example of back translation.
Back translation refers to the process when a translator takes a document translated in another language and translates it back to the original language. Back translation is a way of comparing the translated document with the original document in order to check for clarity and accuracy in the content.