Plate tectonics: a. is probably responsible for some climatic changes that occur on a time scale of millions of years b. may us better understand the cause of the ice age c. may be a key factor in explaining the cooling trend that has occurred since 1940 d. both a and b e. both b and c

Both a and b

Explanation:

The plate tectonics are a process which moves the tectonic plates on the surface of the Earth. As the plates move, they cause the appearance of new continents, destruction of old ones, formation of new oceans and seas, closing in other ocean and seas, formation of mountain ranges and valleys etc. All of this influences the climate on the planet. The ocean currents are directly dependent on the positions and shapes of the continents, and they influence the climate a lot. Also, the manner in which the continents are shaped and placed causes certain climates to occur or not. For example, if there isn't any continental land mass on and in close proximity to the poles, the climate will automatically be warmer and the chances of formation of polar caps, thus Ice Ages is almost impossible.

question

which are human systems?

the amazon rain forest

the appalachian trail

the george washington bridge

the himalayas

the hoover dam

the north american free trade agreement