Scientists believe that the blank (Milankovitch Cycles, sea levels, low temperatures, or tilt of earths axis) explain why earths(climate has, low temperatures have, sea levels have, or tilt of earths axis has) fluctuated between glacial periods and interglacial periods. Please help:/

Planet earth is known for its evolution during its life time, as at first there was all water across the planet and then came a period on the planet all of the factors including the climate changed very drastically, making it more different for the being as well to survive. It was all caused by the displacement or movement of the optimum level of energy from one region or sphere to another, as there are different levels of energy potential inside each space i.e lithosphere, biosphere and atmosphere. When the earth was covered by a thick layer of gasses and there were less sunlight for the earth to observe, the planet observe a more different climate back then as there was formation of glacial across the globe. While, there was time on the planet when the inter-glacial period hit and there were less to see from such factors like glacial masses on the face of the planet. This whole fluctuation of climate happened across centuries as the earth we see today is much different from the one which was many millions before.                                                                                                                

                                                                     

The answer would be d because x,y = male and x,x = female so x,y is male so xxy is male with a female trait!

The answer is a because - is an direction