Number a is a correct one
Answer
The type of boundary formed when lithospheric plates collide is called Convergent boundary
Explanation
When plates of the lithosphere collide, they form a sub-duction zone where the denser plate will be subdued underneath the less dense one. The one subdued later melts and get destroyed. This boundary occurs when; ocean crust meets ocean crust, when oceanic and continental crust meet and where continental crust meets continental crust.
Answer:
a) force = mass * acceleration
so,
F=87*9.8
=852.6 N (newtons)
b) in the real world, the force affecting the rste of fall is most likely Air Resistance!
Answer:
The genes are expressed in analogous regions of fly and mice embryos.