The first sino Japanese war resulted in Japan invading Korea ( I had to make it longer )
Out of all of them, Switzerland would be the one that was neutral.
assuming efficiency of each man to dig trench, in one day, for one hour is constant,

so one man, working for one hour in one day can dig 1.5 m
so 8 men, working 3 hours a day and will take, say $d$ number of days and efficiency will be constant. so,
$\frac32=\frac{220}{8\times3\times d}$
$\implies d=\frac{55}9=6.12$
Answer:
One long term effect was the population decrease. Once populated villages and towns were left to rubble and ruins after the black death hit. Large, working expanses of land were left to deserted wilderness, crops were left to rot in the ground, and cattle were left to roam around until they perished.
Explanation: