Although tanks were slow, how were they beneficial?

They are beneficial because, they are like armored people with bigger guns. So unless you can somehow manage to stop it or escape to sea and leave your country to mercy of the tanks than you'll have to destroy them somehow. So, they inspire fear and do heavy damage on the battlefield on a land based battlefield.

Explanation:

a and b!

dfroos means which is a and b

sitting in that one chair where he could get shot at was his worst decision.