Answer:
Don't make so much noise. Noriko <em><u>is trying</u></em> to study for her ESL test!
Explanation:
In the given sentence, the speaker is seen asking or rather ordering the others to not make any noise. And the verb in the blank will be in the present continuous tense, as the act of studying is still an ongoing act.
Considering the verbs in the given sentences, "make" is in the present tense which makes the tense in the next sentence a present tense too. And, the helping verb "is" emphasizes the verb, making the next sentence into a continuous form.
Thus, the final sentence will be
<em>"Don't make so much noise. Noriko </em><u><em>is trying</em></u><em> to study for her ESL test."</em>
