He studies hard ___ fail in the exam. A. not to
B. so as not to
C. in order to
D. so that

A not to fail

studying is necessary to pass and ensure success

A not to fail in the exam

Explanation:

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.