music: What Pete Seeger composition became the peace campaigners anthem?

Questions

Circuits can be wired in series or in _________?

Circular staircases in firehouses are a tradition began to keep what from coming upstairs?

City in eastern china, situated on the Huangpu River, a tributary of the Yangtze River, near the Yangtze's mouth to the east China Sea?

City in eastern Iowa, on the Mississippi River, seat of Clinton County?

City in northeastern Germany, capital of a United Germany from 1871 to 1945 & again since 1990?