What did the countries of Europe established in China during the 1800s

(this is just for fun) "alexander hamilton had a torrid affair and "(hamilton reference) : )

What led to the environmental damage that caused the dust bowl? 1. desert winds emerging from the southwest 2. rotating crops every year and having fallow land 3.overplanting throughout the great plains 4.a year-long drought

What are new social classes emerged due to advancement in agriculture ?