What was mohorovičić's observation?
seismic waves travelled at constant speeds.
seismic waves penetrated all earth's layers.
seismic waves could not go through the brittle crust.
seismic waves travelled at varying speeds.

Seismic waves traveled at varying speeds.

Explanation:

The Moho Discontinuity was discovered by one Croatian seismologist, Andrija Mohorovicic. He realized that the speed of a seismic wave depends on the density of the material the wave is moving through. Mohorovicic interpreted the acceleration of seismic waves observed within the Earth's crust as a change in composition of matter within the Earth.

the answer would be 3

you did not attach the discourse, but i assume it to be the discourse on the origin and basis of inequality among men (the original titile in french is: "discours sur l'origine et les fondements de l'inégalité parmi les hommes"), also know as "second discourse". in this discourse, jean-jacques rousseau emphasizes that private property is the basis of all inequalities.

therefore, what enabled the old regime to maintain as long as it did was private property.