Sudoku - help needed!

I love Sudoku puzzles. I read a few years ago that doing Sudoku puzzles might help keep my brain active and delay the onset of dementia or other memory issues that we senior citizens seem to suffer. At this point I hope that is true but really don't care too much. I have become a Sudoku fan and really enjoy doing the puzzles.

I use http://www.websudoku.com/ for its free puzzles, and for a year or so I have been doing the EASY puzzles. I got to the point where I could do all easy puzzles and got my time down to around 8 minutes. I think the web site says the average time for their easy puzzles is around 6 minutes. Okay, I never said I was fast! I can just complete them all successfully.

Lately I have been trying the MEDIUM difficulty puzzles, and after a while I have run into a stone wall. I can do most of them, and it takes me 20 minutes now to do the medium puzzles. BUT, I have run into two MEDIUM puzzles so far that have me stymied.

I would like someone who can solve this puzzle to please give me a hint. One possibility would be to give me the next move and to explain the logic and how the answer was determined. Another would be to just explain the logic necessary to determine the next move, and I would be perfectly happy with that. Anyone?

I should mention that since I have been doing all of these online that I do not have a pencil and paper to use. Some people suggest writing the "possibilities" for the boxes inside the boxes with a pencil in a small font. Then, examining all the possibilities would help determine the next move. That may be true and may indeed be what I have to do, that is, get me a pad and start filling in possibilities. If that is the way to proceed, fine, but I am hoping there is yet (at least) one more trick I have not learned. Anyone?

Please write me at pcdoc@brpcdoc.com if you can help.

 And thank you!

Here is where I have run into a wall. It's kinda neat that all 3 incomplete rows contain the same numbers. I have not run into anything like this so far. The numbers in blue are the ones I have entered so far.

Happy New Year!