【英语时差8,16】落叶美景从何而来（上）

As the dog days of summer trot¹ into autumn, you might start thinking about one of nature’s most spectacular shows–the annual fall foliage² display that can break out like brilliant slow-motion fireworks in woodlands around the country. Let’s face it though, not all fall leaf displays are created equal. While some autumns explode like the Fourth of July, others fizzle like a wet roman candle. What Makes Some Year’s Leaf Displays Better Than Others? Actually, a few different processes work together to make an autumn leaf display. As daylight shortens at the end of summer, a layer of cells grows at the base of each leaf stem, cutting off the water supply like a cork³. Along with other metabolic⁴ changes, this stops production of green chlorophyll in the leaf. When the chlorophyll breaks down, it unmasks yellow or orange pigments⁵ that have been present in the leaf all summer, but only now become visible.

1 trot   

n.疾走，慢跑；n.老太婆；现成译本；(复数）trots:腹泻（与the 连用）；v.小跑，快步走，赶紧

参考例句：

• They passed me at a trot.他们从我身边快步走过。
• The horse broke into a brisk trot.马突然快步小跑起来。

2 foliage   

n.叶子，树叶，簇叶

参考例句：

• The path was completely covered by the dense foliage.小路被树叶厚厚地盖了一层。
• Dark foliage clothes the hills.浓密的树叶覆盖着群山。

3 cork   

n.软木，软木塞

参考例句：

• We heard the pop of a cork.我们听见瓶塞砰的一声打开。
• Cork is a very buoyant material.软木是极易浮起的材料。

4 metabolic   

adj.新陈代谢的

参考例句：

• Impressive metabolic alternations have been undergone during embryogenesis.在胚胎发生期间经历了深刻的代谢变化。
• A number of intoxicants are associated with metabolic acidosis.许多毒性物质可引起代谢性酸中毒。

5 pigments   

n.（粉状）颜料( pigment的名词复数 )；天然色素

参考例句：

• The Romans used natural pigments on their fabrics and walls. 古罗马人在织物和墙壁上使用天然颜料。 来自辞典例句
• The original white lead pigments have oxidized and turned black. 最初的白色铅质颜料氧化后变成了黑色。 来自辞典例句