Which of these was a natural barrier in China’s Western lands that slowed is development in ancient times

Which of the following is an example of the pull factor known as economic migration? a. better educational opportunities pulling people towards a new country b. mexican laborers entering the us to work in agricultural jobs c. joining family members that are already in a new country d. crop failures driving people away from their country i am unsure on this question, i was thinking b? but i could be wrong.

Why did noli me tangere have such a big impression on the narrator?

What was the significant advancement of the caravel? a. it could sail with the wind c. it could sail against the wind b. it could sail at night d. it was motorized