1. what causes a continental shield to form?
a. the formation of mountains and their subsequent erosion at convergent plate boundaries
b. the subduction of oceanic lithosphere under continental lithosphere
c. the partial melting of magma under a continent
d. the collision between two plates of continental crust
2. the stable platform has developed from a series of
a. mountain belt erosion followed by isostatic adjustment
b. volcanic eruptions that deposit thick layers of lava followed by periods of metamorphism
c. rising and falling sea levels and their accompanying cycles o

1- Option (C)

               2-Option (B)

Explanation: Continental shields are the region within the continent where there is no active tectonism or it can be considered to be a stable region. Continental shields are formed in the region where partial melting of the crust takes place and the magma rises up and gets cooled because of the low temperature and gets solidified forming crystalline rocks such as granite.

 In due course of time, partial melting below the crust stops and the crystallized rocks gets metamorphosed and forms a stable craton.

Thus the correct answers are option (C) and (B).

need to see circuit to get time constant

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.