Based on what you have learned about World War I, which aspect of trench warfare do you think was hardest on the soldiers?

I think all the diseases spreading in the trenches scared them more than the people shooting at them. I say this because you can defend yourself against the attacks of the enemy, but you can't do much against an illness in a stagnant damp trench.

Explanation:

what an awful time to be alive.

porter is writing economic history because he is focusing on the cost of developing vaccines.

letter a is the answer