So it happened like this. I bought a brand new fuji touring. Rode it for about 100 miles and brought it to the shop to find out why the shifting isn't 100%, not even close to 60%. After some adjustment, the mechanic pointed out some teeth in my smallest cog are bent. He said it must from cross chaining. I have never use the big ring and the biggest cog or small ring with the smallest cog. But I have use the middle ring with the smallest cog a lot. He said it must be from that. I am not sure if he is right. It's brand new bike...

Anyways, instead of using the middle ring with the two smallest cogs, I think I can do better by using the big ring with the 4th and 3rd small cogs

And regarding to the shifting, it turned out the rear derailleur was not aligned properly. They did some adjustment again, it's better, but still not 100%...