Alguien me puede ayudar porfa? porque la tierra siempre cambia?

It is not known why earth changes always. However, it is a truth that Earth changes each day. The details are given in the explanation. Also, anything that exists is subject to change, and this is a universal truth, and that's why earth also changes sometimes through climatic change, and sometimes with the time.

Explanation:

The mother earth has seen all colors of life, but God keeps making new colors daily. There was once ice age, and then came Ice-free age. And even when we didn't exist, forests used to catch the fire through lightening. The volcanoes used to erupt during those days as well. And now the refrigerators. air conditioners. industries and all are depleting ozone layer and a lot out of these are causing an increase in temperature due to CO2 effect in the atmosphere. Arrhenius once studied the rate of rising temperature in the earth's atmosphere and proved in around 1896 that the temperature of the Earth is increasing, and with further studies, we are now up with the most accurate statistics related to earth's climate. If we do not take the initiatives then mother Earth might soon not be as good as it is used to be for living. Hence, we have to take care of the climatic condition of mother Earth and discard everything harmful.

two jet streams that directly affect the formation of weather in the continental part are a polar jet and a subtropical jet. they are responsible for the transportation of weather systems, which directly affect people. the polar front is the boundary between cold air from the north pole and warmer equatorial air. both the polar jet and the subtropical jet blow from the west to the east, and follow the boundary between cold and warm air.

the strongest jet streams are polar jets, while subtropical jets are somewhat weaker.

the right answer is c. the polar jet stream is generaly stronger than the subtropical jet stream.