Why is the answer "will have worked" but not "will have been working"?

Which of these can an adverbial clause modify?

What is the key similarity between the characters of gerasim and vladimir ivanich in tolstoy’s the death of ivan ilyich?

Which best explains this excerpt’s purpose in the novel’s plot structure? the excerpt creates conflict between characters as part of the rising action. the excerpt provides background information on a character as part of the exposition. the excerpt returns a character to equilibrium as part of the falling action. the excerpt is the point of greatest tension and acts as the climax.