Answer:
c
Explanation:
if it was no change it would not make sense, but c
the area with low pressure will be more dense in the area with high pressure will be less dense
Answer:
The spec house is a speculative venture for the builder, meaning it was built with the intention of selling it for a profit, as-is or with minimal changes. Spec houses are plentiful when the economy is healthy because builders can sell them quickly and use the profits to build more.
Explanation:
Because Cyanobacteria appeared
Cyanobacteria's excrement formed a lot of oxygen in the atmosphere which make the earth temperature cold
This allow a liquid water to formed on the surface ( because if the temperature is too high, the water will evaporate) and eventually formed oceans
