Well done Zhuo Ren. Good steady thinking and you finally managed to out-maneuver and out-think your opponent. It all shows on the board. What did you think of Jimmy's sacrifice? Does it reflect on his mental state? How he makes decisions generally?
You asked me at my home what is mental strength. I hope you can see the answer now. It's the ability to cut through their titles and their manufactured fat numbers and see the actual quality of their chess/thinking. It's the ability to see through false friends bearing "gifts" so that they can enter your mind like thieves in the night to steal the most valuable possession you have. Your self belief, your confidence.
Mental strength is the ability to see all that and then not waver in the decision you need to make. Learn and remember this and you will go far in life.
All my best
ps: Well done girls against Canada. Fighters all. We are proud of all of you.