Answer:
DNA is double stranded? if that is your question.
Explanation:
An antibiotic ointment could be used for a woman's vagina lips in case of tearing in natural childbirth which can happen if the baby is say a little too large for the opening as long as not too large to require a caesarian.
One method I know of is comparing a sample of the rock to other samples which the scientist already knows the age of. I forgot what this method is called but I know it's used by lazy scientists that use other scientist findings like the age of a rock to compare to their own work