Do you mean WW1 ? People started migrating through disguise and things like that. Not sure if I’m 100% correct but it’s a starting point
option 2 is the right answer because it printing a book and the other ones are science
Answer:
hmm I don't know-how to explain
The skeletal system works with the muscular system to help the body move. Marrow, which is soft, fatty tissue that produces red blood cells, many white blood cells, and other immune system cells, is found inside bones.
