Which situation shows the presense of oxygen in a material? I. Lighting of candle
II. Burning of fuels
III. Combusion of engines
IV. Putting off a lighted candle

A. I, II and III
B. I and IV
C. I and II
D. All of the above

labor leaders and organizations had the power to demand it.

explanation:

workers got a five-day workweek because the bcea protects and respect the rights of the employees. labor leaders and other groups demanded it.

world war i began in 1914, after the assassination of archduke franz ferdinand, and lasted until 1918. during the conflict, germany, austria-hungary, bulgaria and the ottoman empire (the central powers) fought against great britain, france, russia, italy, romania, japan and the united states (the allied powers). to new military technologies and the horrors of trench warfare, world war i saw unprecedented levels of carnage and destruction. by the time the war was over and the allied powers claimed victory, more than 16 million people—soldiers and civilians alike—were dead.

explanation:

the answer is a new goverment.