What does this phrase mean"to spoil by introducing foreign matter"​

Why does black lung aka arthur morgan let only jhon and abigail go and not sadie in the last chapter

Which term best describes the progressive era

“second, the reviewer must know the current trends in movie-making. what types of technology are available? are audiences more drawn to low-budget, independent films, or huge, explosive blockbusters? ” the passage above is explaining a. important information you must have before watching a movie c. what a reviewer must understand to write effective reviews b. why it is impossible to understand the movie business d. how to break into the cinematography business