Read this excerpt from "Why Are They Called Black Holes?" After many millions or billions of years, the star runs out of hydrogen and energy. Then the star "dies" and collapses into a dense little ball with tons of gravity. Albert Einstein’s theory of relativity predicted that black holes would have to exist if a dead star had enough gravity. Using Einstein's theory, astronomers calculated that if a star more than three times as heavy as our sun died, the force of gravity pulling matter in could overwhelm any other force pushing matter out.

ON A EXAM PLEASE HURRY

In this excerpt, the author makes a connection between a scientific theory and

the calculations that scientists make.
the beginning of a star's existence.
the idea that all things live and die.
the question of why gravity exists.

Read this sentence:somebody save the smoke! the nomadic tribes move to a new location each season. which word provides a clue to the meaning of nomadic? new season move location

Part a which statement best describes a central idea in this narrative? in times of tragedy, it is difficult to determine how best to be of service. in times of crisis, people prefer to be alone. young people tend to look to older people to take action in times of tragedy. when people publicly commit to being of service, they are more likely to follow through. part b which detail from the text best to shape the central idea in part a? "'i thought you might have too much going on already. i saw everyone post online.' martin said, 'i don’t think anyone wanted to be in the way today, so i’m glad you came.'" "finally, he said, 'i don’t know what to do. i guess i should tell him to let me know if he needs anything, but that doesn’t feel like enough.'" "he wondered how many people would actually show up to out and how many would simply hope that enough others did." "he explained to her that martin’s mom had died, and told her how he felt about his friend’s loss. 'what do you plan to do for him? ' his mother asked."

What exaggeration about him smiley does the narrator of the notorious jumping frog of calveras county make