One major difference between opera buffa and opera seria is: A. Opera seria is meant to be staged in sections, while opera buffa is meant to be watched all at once.
B. Opera buffa has comic elements, while opera seria is strictly dramatic
C. Opera buffa makes fun of the middle class, while opera seria makes fun of the upper class.
D. Opera seria was a form of 19th century opera, while opera buffa was a form of 18th century opera

i would think it's industries and hydroelectric power

polling is a process and the outcome is not involved in the process itself.

the outcome, which is an unfavorable rating for a particular candidate is not affected by the mechanical process of polling.

it rather depends on the number of people voting in favor of the candidate.

this is an outcome of people's preferences.

i think it was   tsar alexander ii

the section of the chart that represents a point at which a bill needs approval from a majority of people in both chambers to advance is j, as this is the only section before the bill becomes law which has both rows (symbolizing the chambers) converging into one, meaning that the two parts of the congress have to approve of it before it can march on with the process.