<em>When</em><em> I looked at the museum map I noticed a new insect exhibit.</em>
Explanation:
In this task, we have two independent clauses (they can stand alone) that represent two sentences. Our job is to merge them into one sentence while being careful not to deviate its meaning. So, there are two possibilities: the first one is to put <em>when</em> in the beginning of the sentence, so it can look like this: <em>When I looked at the museum map I noticed a new insect exhibit.</em> The other option is to put <em>when</em> between these two independent clauses: <em>I looked at the museum map when I noticed a new insect exhibit.</em> Looking at these two possible solutions, the first one seems to have a more logical order of actions.
