Question Which of the following is the MOST appropriate sentence to begin a formal acadernic essay about the
discovery of gravitational waves?
A binary star system is made of two stars, which both orbit around a shared barycenter.
Another important concept for understanding gravitational waves is that of angular momenturn.
O A major breakthrough was announced in 2016, when scientists reported they had heard and recorded
gravitational waves for the first time.
But even Einstein, who had some idea about gravitational waves, wasn't totally sure they were even real.

the 3rd one

Explanation:

when starting any essay, its good to have a hook, something to get the reader relatively interested in what you are writing. The hook in this case is the 3rd one since it talks about gravitational waves which means it stays on topic and it provides a recent discovered breakthrough which can make the reader interested.

A binary star system is made of two stars, which both orbit around a shared barycenter.

Explanation:

you need to know what you have learned: )

in the story "marionettes inc," in the last line of the story, braling two is referred to by the narrator as the "someone." what does this new identifier imply and how does it add to the drama of the closing scene?