4-2最後一段翻譯

Evident indicates that more than half of all life on the earth has been wiped out in five mass extinctions over the past 500 million years.Scientific hypotheses explaining the causes of these mass extinctions include asteroids colliding with the earth,large-scale emissions of toxic hydrogen sulfide(H2S) from the ocean into the atmosphere,and climate change.Such mass extinctions opened up opportunities for the evolution of new species and shifts in the locations of some ecosystems.On a long-term basis,the four scientific principles of sustainability,especiallybiodiversity,have enabled the earth to adapt to drastic changes in environmental conditions.

證據顯示在地球上多於半數的生命在過去的5億年的5大滅絕中毀滅。科學假說解釋這些大滅絕的原因包括小行星撞地球,大規模有毒的硫化氫從海洋散發到大氣中和氣候變遷。這樣的大滅絕提供新物種的演化和轉移在生態系統中的位置的機會。在一個長期的根據,4個永續性的科學原則,特別是生物多樣性,已經使地球能夠適應環境狀態方面的激烈變化。

3-4 p49 5.6段翻譯

The B horizon(subsoil) and the C horizon (parent material) contain most of a soil's inorganic matter,mostly broken-down rock consisting of varying mixtures of sand,silt,clay,and gravel, much of it transported by water from the A horizon.The C horizon lies on a base of parent material ,which is often bedrock.The spaces,or pores,between the solid organic and inorganic particles in the upper and lower soil layers contain varying amounts of air(mostly nitrogen and oxygen gas) and water.Plant roots use the oxygen for cellular respiration.As long as the O and A horizons are anchored by vegetation,the soil layers as a whole act as a sponge, storing water and releasing it in a nourishing trickle.


B 地平線(下土層) 以及 C 地平線(母質層) 包含大多數土壤的無機物，大部分的岩石組成是由沙、泥沙、泥土、和碎石混合變質而成，而這些組成大部分都是被水從 A 地平線(表土層) 搬運過來的。C 地平線 位於一個母質層的基礎上，這經常是床岩。在上部和下部土壤層的固體有機和無機物粒子之間的空間或孔洞包含著不同量的空氣(氮和氧為主)和水。植物的根把氧用於細胞呼吸。只要 O 地平線 和 A 地平線 被植物固定，泥土層就可以當作是一塊海綿，儲存水分和釋放水分保持滋養。