Answer: UUUAUUCGCGGU
Explanation: Remember the base pairing rules: cytosine with guanine and adenine with uracil. To compliment the given strand, you'd have to choose the base that would pair with each individual nucleotide. Since mRNA has no thymine, the adenine must pair with uracil instead. However, it does have adenine to pair with the thymine, even if it doesn't have any of its own.
Hope this helps,
Lacia
