Usually USA is a mess in changing but this case was a clear damage caused by the Brazilian girl. I think this time it's fair that USA had the possibility to run again (all alone) and then qualify for the final.
Don't remember China, but the Japanese were amazing in changing. That's the right strategy if you don't have super star sprinters and want to get to the final anyway.
In men only GB from Europe will run the final, in women we have GB, Germany (a young relay that I really like) and the usual Ukraine... Netherlands is out and that was because of..... Daphne Schippers! She's still shaken by her 200m final....
I meant Chinese Men Poor Dafne. Though she should be proud of herself. Unlike most of the sprinters, she's focused solely on sprints only two years!