Which one? this is a test so i need answers urgently!

Is "they" an unstressed or stressed syllable?

Afruit stand has to decide what to charge for their produce. they decide to charge \$5.30$5.30dollar sign, 5, point, 30 for 111 apple and 111 orange. they also plan to charge \$14$14dollar sign, 14 for 222 apples and 222 oranges. we put this information into a system of linear equations. can we find a unique price for an apple and an orange?

Do not use this medicine with milk, cheese, or other dairy products. what end punctuation needs to be added to the above bolded word?