Simple, we weren't around during that time, so we made theories and conclusions to when life evolved on earth.
Answer:
It has a thick atmosphere of hydrogen and helium. (d)
Answer:
Earthquakes and volcanoes.
Explanation:
Earthquakes and volcanoes are responsible for the movement of these continental and oceanic plates because movement of these tectonic plates occurs due to convection currents in the molten rock in Earth's mantle present below the crust. Earthquakes and volcanoes are the short-term results of these tectonic movement while the long-term result of these tectonics causes the movement of entire continents over millions of years. The density of crust is 2.2 g/cm3, the density of upper mantle is 3.4 g/cm3, the density of lower mantle is 4.4 g/cm3, the density of outer core is 9.9 g/cm3 and the density of inner core is 12.8 g/cm3
Answer:
C
Explanation:
For example, if you throw rubbish on the floor or in the sea , the environment is bad. therefore , all the mess humas create it will all come back to us in some way
