Why might we expect other solar systems to be similar to ours?

What would happen to kenya's pyramid if there was a rapid decline in its: a) birth rate b) death rate

Volcanic irruption is most likely to be violent when a) volcanoes near to the sea b) the neck of the volcano is sealed by a plug c) the lava is viscous d) the lava reaches the surface through a fissure e) the volcano is on the ocean floor

:calculate the sum of the interior angles of a 13-sided polygon.