Answer: They are directly caused by the gravitational pull of the Sun.
Explanation:
Water waves are caused by a whole number of factors, they include,
1.) Local winds
2.) Distant wind
3.) Air pressure
4.) Seismic sea wave
The gravitational pull of the sun and moon on the earth also causes waves. Although the sun's gravity also contributes to the waves, but its effects are smaller and serve mostly to vary the heights of high and low tide.
Barley. Grains remain an important part of the Russian economy.
Asthenosphere is the answer of this question. It best describes the all above mention properties.
Asthenosphere is the the upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.
The answer is D. Ecosystems experience change through human activity and natural events