Duke ACT superscoring?

1st try: 31 composite with 34 writing, 32 science, 30 math, and 28 reading.
2nd try: 33 composite with 35 writing, 30 science, 30 math, and 35 reading.

Do i send in both scores because my science score dropped and I want them to see the 32 subscore? Or will the 31 hurt me and I should just send the 33?

Call Duke directly and ask them. Duke will give you a better answer than some random person here.