Write a story ending "after all this, I realised that I owe it all to her"​

I met Sarah in a Uber and she was my driver to St.Petersburg. I felt really anxious talking to her after all she’s just another stranger. She has dark black hair, a smile that brightens the night. I asked her how long she has been an Uber for as a conversation starter. She then said:”I only started about a week ago. It’s been really tough lately for me and my roommate on campus.” I felt quite bad for her. She works two minimum wage jobs and on top of that she works as a Uber. As soon we arrived at my grandmas apartment I gave her a tip of $20. She thanked me and said that it’s going to help her tonight. Right when I was about to leave the car, I forgot something: her phone number. I ran back to the car and asked her. I woke up realizing it was all a dream. I took my medicine and went to the kitchen for breakfast. I turned on the tv and the news came on as usually at 7 in the morning. There was a hostage situation in a Uber at 6:30. The news paper came in.
The headline for today was:”After all this, I realized that I owed it all to her” those were the last words of a emotionally disturbed man after taking his life on camera.

Okay, biology isn't exactly my strongest subject (it never has been), but i'm pretty sure the answer is nucleotides. dna is made up of nucleotides. each nucleotide contains a phosphate group, a sugar group, and a nitrogen base. there are four different nitrogen bases: adenine (a), thymine (t), guanine (g), and cytosine (c). a always pairs with t, and g always pairs with c.