Which enlightenment philosopher wrote the social contract?
a. jean-jacques rousseau
b. john locke
c. baron de montesquieu
d. thomas jefferson

The correct answer is A. The Enlightenment philosopher who wrote The Social Contract was Jean-Jacques Rousseau.

Explanation:

The Social Contract is a book written by Jean-Jacques Rousseau and published in 1762. It is a work on political philosophy and deals mainly with the freedom and equality of men under a state instituted through a social contract.  It is said that this book was one of the many inciters of the French Revolution for its political ideas.

The correct answer is - D. To prevent snow build-up.

The slanted roofs are a very common feature on the buildings in Russia and Finland, and the reason for that is the safety issue. By having slanted roofs on the buildings, the large amounts of snow are not able to build up over the buildings, but instead, as the snow is building up, the sharp angle of the roof contributes that the snow's weight pushes it downwards and on to the ground.

If the roofs are not made in this manner, than the snow will build up, and we are talking about 70-80 cm of snow, or even more than a meter and a half at some places. That big of an amount of snow will weigh a lot and will manage to break up the roof of the buildings and even their frames.