Part b: which detail from the passage supports the answer in part a

the correct answer is a. how to make proposal that works.

indeed, the register is quite formal and the tone is especially objective as it avoids the use of the first and second person singular (i, you) and opts instead for the third person plural which is more impersonal and focuses on the data and the argument that is being developed by the author. the formality adds the impression of respectability to the work and the impersonality adds objectivity to it.

invention of the washing machine

in the past, people used sticks and stones or scrub boards to clean their clothing. as it was sweaty, backbreaking work, we owe a world of to james king because he created the model for the modern washing machine in 1851. the most important issue was that this machine cleaned clothes while a person cranked the handle. doing this made people who used it develop strong muscles in their arms. later, in 1908, alva j. fisher created an electric washing machine named thor. this one was not the first automatic washing machine. however, it was one of the most popular models at the time.

your answer is c) experiments with water vapor showed that elements combine in specific proportions.

i literally just read the book and studied it for months so i could you, but i need to know where these questions are coming from. they are too general.