Clear explanation of why the leaves turn brown through the winter period.

    There are a number of reasons why the leaves turn brown in winter.

    The earth further away from the sun in winter, the earth spins in a egg shape, the bottom of the egg is nearest to the sun which is summer. For plants to make food it has to go through a process called photosynthesis. Photo means light and synthesis means energy. The plants absorb light using their leaves, because the sun is far away there are less light beams for the leaves to absorb. Light on its own cannot make the plant grow it also needs water which only can be absorbed by the roots underfround.

    What happens to the water?

    Because the sun is further away, not enough heat is distrubuted into the earth, so all the water gets frozen and cannot be sucked in by the roots.

    關(guān)于在冬季，葉子為什么變黃的清楚解答。

    冬季里葉子為什么變黃有許多的原因。冬天的地球離太陽(yáng)很遠(yuǎn)。

    地球（圍繞太陽(yáng)）旋轉(zhuǎn)的軌道是卵形的，在卵形軌道的底部，地球距離太陽(yáng)最近，這時(shí)季節(jié)就是夏天。植物要通過(guò)一個(gè)叫做光合作用PHOTOSYNTHESIS的過(guò)程來(lái)制造食物。PHOTO的意思就是光，SYNTHESIS的意思是能量（聚合）。植物通過(guò)葉子來(lái)吸收光能。因?yàn)椋ㄔ诙�天）太�?yáng)離地球越來(lái)越遙遠(yuǎn)，葉子可以吸收的光越來(lái)越少。植物生長(zhǎng)不僅依賴(lài)光，還需要水分。植物通過(guò)地下的根來(lái)吸收水分。

    那么水怎么了呢？

    因?yàn)樘��?yáng)離地球太遠(yuǎn)，給與地球的熱量不夠多，所以地上的水結(jié)了冰，根就不能吸收水分了。