According to the video, blank were the first engineering marvel seen in history. A. pyramids
B. bridges
C. roadways
D. water aqueduct systems

The correct answer to this open question is the following.

Unfortunately, you did not attach the video or a link to it. Without the video or the name of it, we do not know what you are talking about.

However, trying to help you, we can comment on the following.

Pyramids were the first engineering marvel seen in history.

The reason why is that Pyramids are the oldest constructions known to archeologists, scientists, and historians. There are pyramids, like the Egyptian Pyramids in Giza, Cairo, that had been dated from thousands of years before Christ. Modern research affirms that the pyramids could be older than mainstream science has established.

Architects admire the mathematics and engineering knowledge of ancestral Egyptians who were able to build those magnificent pyramids without the technology needed to build them. Even today, those pyramids are impossible to build. That is why these pyramids remain a mystery.

they wanted the u.s. to fight on the side of the central powers.

here are some major conflicts i found. maybe pick one and do more research on it. (cause i ain't writing 6 paragraphs)

in 1877, the nez perce war took place.

1881 - president james garfield was assassinated.

1882 - the chinese exclusion act was passed.

1883 - a decision in the civil rights cases legalized racial segregation in the united states.

1887 - the dawes act was passed.

1893 - the panic of 1893 took place. (what a creative name)

and there are probably other topics you can find if you just search up "united states timeline," or "conflicts in the 19th century for america."

then once you find a topic you like find out how it affected the people of america and what not. (sorry if this feels a bit short changed, history was and never will be one of my strong topics)