Wendy - I haven't put on my headphones yet - I'm off to do some early in-person voting first - but I do see a couple things when I open the chapter in Audacity.
1) Your closing silence is only 1-and-a-smidge seconds long - it should be 5 seconds. You can add silence in Audacity by going to the end of the recording (shortcue: press 'k') and selecting 'Silence...' from the 'Generate' menu. A box will open up and you can enter how many seconds of silence you want to add.
2) There are many places in the recording where your volume level goes all the way to the top. This creates clipping, which gives the recording a harsh sound. If your levels when you recorded were too high the clipping is recorded in and there's nothing you can do about it at this point (beyond recording the section over). To avoid this in the future set the record slider in Audacity lower. Don't worry about it being at 7 or 3 or whatever - the ideal level depends on your microphone and related hardware, how close to the microphone you are and your voice. In general if you see the level on the record meter go into red as you are recording you may be in danger of clipping.
For now, you can try lowering your overall volume in this recording by 2.9 dB and see if it sounds bad (clipped).
I'll listen to your chapter when I get back.
'Till later, then.