Why did the Japanese feel that they needed to invade China?

Seeking raw materials to fuel its growing industries, Japan invaded the Chinese province of Manchuria in 1931. By 1937 Japan controlled large sections of China, and accusations of war crimes against the Chinese became commonplace.

the number of calories in each pack of cookies has a greater variation than the number of calories in each pack of crackers.

most people now work in jobs where they do one  kind  of work; they are carpenters, bankers, cooks, mechanics, and so forth. likewise, most  businesses produce  only certainkinds  of  goods  or  services, such as cars, tacos, or gardening  services. this feature of  production  is known as specialization.