Why did Lu Hong and her faction of the Red Guard burn their teachers' books?

Which of the following descriptions is an example of the curtual diffusion

Humans during the paleolithic era used fire for each of the following purposes except a. for cooking meat b. for use as a weapon c. for heat and warmth d. for treating animal hides select the best answer from the choices provided

The soviet union and the united states believed in two very different economic systems. what were the names of each?