
Answer:
China should trade Aircraft to Shirt and American should trade shirt to Aircraft.
Step-by-step explanation:
We should make a comparison table between two country
        China America Â
1 Aircraft  40000 100000
1 Shirt      4        2
It is clear that China's labor productivity in aircraft production is more outstanding than America and America's labor productivity in shỉrt production is better.
So China should trade Aircraft to Shirt and American should trade shirt to Aircraft.