题目内容：
回答题We experience different forms of the sun' s energy every day. The sun is the major source of energy for our planet. It causes the evaporation(蒸发) of water from the oceans and lakes. Sunlight also provides the energy used by green plants to make their own food. Much of the energy that comes from the sun never reaches the earth' s surface. It is either reflected or absorbed by the gases in the upper atmosphere. Of the energy that reaches the lower at mosphere, 30% is reflected by clouds or the earth' s surface. The remaining 70% warms the surface of the planet, causes water to evaporate, and provides energy for the water cycle and weather. Only a tiny part, approximately" 0.023%, is actually used by green plants to produce food.
Many gases found in the atmosphere actually reflect heat energy escaping from the earth' s surface back to the earth. These gases act like the glass of a greenhouse in that they allow energy from
the sun to enter but prevent energy from leaving. They are therefore called greenhouse gases.
When sunlight strikes an object, some of the energy is absorbed and some is reflected. Theamount reflected depends on the surface. Dark-colored surfaces, such as dark soil or forest, absorbmore energy.
According to the passage, the root cause for weather changes on the earth is A．the atmosphere surrounding the earth
B．water from oceans and lakes
C．energy from the sun
D．greenhouse gases in the sky
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