I think that the answer is 12. hope this helped! ^^
I would go D, anyone disagree?
Secondary succession happens in a place where there had been living organisms. ... The soil contains little dead vegetation.
During the late 19th and early 20th centuries, one reason political machines grem was because they provided essential services to the immigrants.
Option: C
Explanation:
Immigrants means those who leave their native place and entered into a new country. Immigration mainly occurs due to the pull factors which attract them from their own country. Political machines were used to fulfill the basis needs of the immigrants.
Machine politics came to control the voting system and to reduce the pressure on migrants. To win election machine workers proved very helpful. Election campaign, voting system controlled by the political machine and machine worker.
