add the comma to the sentence

As they studied the film they noticed some rules of science at work

i wrote mine like this

As they studied the film, they noticed some rules of science at work

Right.

thank you

You have correctly added the comma to the sentence. Commas are typically used to indicate a pause or a separation of ideas within a sentence. In this case, the comma helps separate the introductory phrase "As they studied the film" from the main clause "they noticed some rules of science at work." This makes the sentence clearer and easier to read. Well done!